METHOD AND APPARATUS FOR THE MOVING INTERFACE PROCESSING OF MATERIALS

Abstract

A method of moving interface processing of materials, the method comprising: providing a working material; providing an energy source adjacent to the working material; providing for relative controlled movement between the working material and the energy source; activating the energy source such that the energy processes the working material; moving the energy source and/or the working material relative to the other to control the amount of processing of the working material achieved by the energy. An apparatus for the moving interface processing of materials, the apparatus comprising: working material; an energy source adjacent to the working material; a means for providing for relative controlled movement between the working material and the energy source such that the amount of processing of the working material achieved by the energy from the energy source is controlled. An apparatus for the moving interface processing of materials, the apparatus comprising: an anodizing bath; a cathode located in the anodizing bath; a power supply in communication with the cathode, and the power supply configured to be in communication with a working material at an anode connection such that a portion of the working material acts as an anode; a motor configured to accurately and methodically move the a working material into the anodizing bath such that anodization of the working material begins at the edge of the working material furthest from the anode connection and just below the anodization bath, and the motor is further configured to immerse the working material into the bath such that the anodization is moved up the working material towards the edge nearest the anode connection, resulting in generally complete conversion to oxide, except for a vanishingly small or insignificant metal or conductive edge adjacent or at the anode connection.

Description

CROSS-REFERENCES

This patent application claims the benefit of U.S. Provisional Patent Application No. 62/278,104 by inventor David Roberts Winn entitled “MOVING INTERFACE PROCESSING OF MATERIALS,” filed on Jan. 13, 2016, and which provisional application is fully incorporated by reference herein.

TECHNICAL FIELD

The present invention relates to a method of processing materials and more specifically to a moving interface processing of materials.

BACKGROUND

Below are two general examples of processing a workpiece or part to change its material properties, but that are limited to surface layers or are not able to completely convert the entire workpiece or bulk of the material to the processed material, at all, or in a timely fashion. (1.) Anodizing: The conventional anodizing by total immersion of a conducting workpiece (normally metals) connected to an anode into an anodizing fluid equipped with inert conducting cathodes (often Pb or graphite) usually produces an insulating barrier layer of the oxided (or fluorided, etc. for example, conversion of Mg to MgF2) metal workpiece that prevents anodizing the workpiece completely (that is, leaving no unoxided material), and the depth of the anodized layer is limited, leaving unanodized workpiece below the anodized layer. Normally the anodized layer, even if porous, prevents further anodization from occurring, unless new metal is exposed to the electrolyte, and a conducting connection is supplied to the remaining metal. Even in the case of porous anodization, a boundary layer of metal must be left; as the metal anodizes, the ability to conduct current is reduced to near zero, leaving metal surrounded by anodized metal. Using the standard anodizing technique, it would be impossible to anodize a metal foil or plate, or a metal film on an insulator completely—i.e. leaving no unanodized metal. For example, an aluminum film on an insulator would anodize until either islands of metal remained, or a continuous film of metal remained on the insulator. Even if a through-insulator connection to the back side of the metal were provided, isolated islands of unanodized metal would result. The bulk of the workpiece thus remains with metal, and fully or mostly opaque, even if the resulting metal oxide film is highly transparent. (2.) Soft, Gel, Liquid, Slurry and similar Materials Processing: Many plastics and other materials are processed by exposure to light (example: PMMA cross-linked by UV light), heat (example: ceramic greenforms or metallic sintering slurries), electron beams, microwaves, electric current, chemical reagent-based changes, or other energy sources/processing techniques. Generally, the energy or processing technique is exponentially absorbed from the surface of the workpiece into the bulk, producing a spatial gradient into the bulk of the cured material. If the part is thick enough or the process energy limited in time, the interior can remain unprocessed. Many material property modifications on the surface of a workpiece may also inhibit the process from proceeding fully or as rapidly into the bulk of the workpiece. For example increasing the opacity or reflectivity of an optically cross-linked plastic, or the solidification of the material can both prevent a liquid curing agent from diffusing into the bulk.

Therefore, there is a need for a method of processing materials that overcomes the above described and other disadvantages.

SUMMARY OF THE INVENTION

The invention relates to a method of moving interface processing of materials, the method comprising: providing a working material; providing an energy source adjacent to the working material; providing for relative controlled movement between the working material and the energy source; activating the energy source such that the energy processes the working material; moving the energy source and/or the working material relative to the other to control the amount of processing of the working material achieved by the energy.

The invention also relates to an apparatus for the moving interface processing of materials, the apparatus comprising: working material; an energy source adjacent to the working material; a means for providing for relative controlled movement between the working material and the energy source such that the amount of processing of the working material achieved by the energy from the energy source is controlled.

The invention also relates to an apparatus for the moving interface processing of materials, the apparatus comprising: an anodizing bath; a cathode located in the anodizing bath; a power supply in communication with the cathode, and the power supply configured to be in communication with a working material at an anode connection such that a portion of the working material acts as an anode; a motor configured to accurately and methodically move the a working material into the anodizing bath such that anodization of the working material begins at the edge of the working material furthest from the anode connection and just below the anodization bath, and the motor is further configured to immerse the working material into the bath such that the anodization is moved up the working material towards the edge nearest the anode connection, resulting in generally complete conversion to oxide, except for a vanishingly small or insignificant metal or conductive edge adjacent or at the anode connection.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure will be better understood by those skilled in the pertinent art by referencing the accompanying drawings, where like elements are numbered alike in the several figures, in which:

FIG. 1 is a schematic view of a moving interface processing edge anodization apparatus;

FIG. 2 is a schematic view of anodization cell resistance;

FIG. 3 is a schematic view of an anodization process;

FIG. 4 is a scanning electron microscope image showing thin porous anodic alumina film, 700 nm, film thickness of 3.8 μm;

FIG. 5 is a scanning electron microscope image showing thin porous anodic alumina film, 700 nm, film thickness of 3.8 μm;

FIG. 6 is a scanning electron microscope image showing thin porous anodic alumina film, 700 nm, film thickness of 110 μm;

FIG. 7 is a scanning electron microscope image showing thin porous anodic alumina film, 700 nm, film thickness of 110 μm;

FIG. 8 is a scanning electron microscope image showing thin porous anodic alumina film and the high density of pores possible;

FIG. 9 is a scanning electron microscope image showing thin porous anodic alumina film and the results of pore-widening in Aluminum to alumina anodization using standard techniques;

FIG. 10 is a scanning electronic microscope images showing anodic alumina, the film is produced from Al film on glass, before pore-widening;

FIG. 11 is a scanning electronic microscope images showing anodic alumina, and a 2 μm×2 μm square SEM field formed under different anodizing conditions;

FIG. 12 is a plot showing the dependence of the pore size on anodization voltage;

FIG. 13 is a plot that shows the pore diameter as a function of anodization voltage for the samples studied;

FIG. 14 is a plot that shows the center-to-center pore spacing as a function of anodization voltage for the samples studied;

FIG. 15 is an image of an early test of an aluminized slide after anodization;

FIG. 16 is an image showing shows the results of refined programming of the EA rig;

FIG. 17 is an image of a normally illuminated glass slide with 4 edge anodizations;

FIG. 18 is an image of a free-standing alumina film;

FIG. 19 is a drawings of cartoons of light trapping in a plastic scintillating fiber;

FIG. 20 is front view of the fiber from FIG. 19;

FIG. 21 is a cartoon of light transport by total internal reflection;

FIG. 22 is an image that shows a MEMS-fabricated silica fiber;

FIG. 23 is a perspective view of an example of a conventional Z-axis connector using indium bump bonds;

FIG. 24 is a schematic of a stress relief anodization apparatus; and

FIG. 25 is a schematic of a roller apparatus.

DETAILED DESCRIPTION

Moving Interface Processing (MIP) of Materials

The disclosed methods described herein are controlled movement of a processing energy or process technique. A specified small area, slice or volume is processed and the process energy or technique is then moved methodically through the entire unprocessed volume of the workpiece. The process energy may be electric current as in anodization, focused or delivered UV, visible, IR or microwave electromagnetic energy, chemical energy, thermally conducted energy or other techniques where the processing normally does not penetrate a part or workpiece to sufficient depth. The workpiece is moved relative to a fixed process surface or volume, and/or the processing technique surface or volume is moved relative to the fixed workpiece.

Some uses of the disclosed method include: a) Complete or much thicker processing or anodization of metal parts, where an edge of a metal workpiece is methodically immersed at controlled rates into an anodizing bath; b) Liquid or soft plastic crosslinking/curing of complex shapes via injection of light over the volume via (for example) UV focusing or optical fibers, or capillary injection of chemical hardeners; c) Ceramics or metal sintering from greenforms via conductive heat or electrical Ohmic energy. The disclosed methods also include a form of 3D part manufacturing based on curing a 3D part out of a volume of precursor material by rastering processing throughout the volume of a precursor (plastic, metal sintering slurries, ceramic greenforms), rather than by additive 3D printing.

a) Moving Interface Processing of Materials—The Slice/Layer Processing Case—An Outer Surface Process Section Moving Through the Workpiece to a Far Surface

The disclosed method is a materials modification process that includes the technique of supplying a surface, edge, layer, or restricted volume of a workpiece to some source of process energy or process technique that is used to modify the material of the workpiece, starting from a specific place on the surface of the workpiece, and moving that process surface methodically through the workpiece. A planar slice of the workpiece maybe envisioned where the processing is taking place, but in principle, the slice could be any surface shape. At controlled rates of speed and of process energy-density delivery, the workpiece is methodically exposed to process energy or processing, starting from one surface, edge, layer or restricted volume of the workpiece, rather than the entire workpiece at once, with the processing restricted to a surface or small volume, slice by slice. That processing surface or volume or layer or “slice” is then moved through the entire volume of the workpiece to the unprocessed regions, controlled so that the entire workpiece is uniformly processed. The motion of the energy or process technique exposure is directed away from the original layer, surface or edge, until the entire workpiece has been processed.

This moving surface process is useful in cases of materials modification processes such that if a three-dimensional workpiece were otherwise fully exposed to the process or process energy source on its entire outer surface, the resulting processed surface layer would self-limit the energy/processing delivery into the bulk of the workpiece, and so the entire bulk is not processed; rather, just a surface layer is processed which prevents or slows further processing of the bulk. In one example, metal anodization almost always self-limits anodization of the entire workpiece, as it creates an insulating barrier film, so that immersion of a metal workpiece into an anodizing bath only anodizes a surface film and not the entire metal. Another example is a thermally driven process, where a workpiece is normally immersed into a heat source or bath, and the process makes the processed material thermally insulative, thus inhibiting the speed of processing. Instead, heat energy is injected into one edge or layer or “slice” of the workpiece and the slice of injected thermal energy is then controllably moved towards the far edge of the workpiece, enabling a much thicker layer or complete processing of the workpiece to be produced. In another example, UV curing of plastics can result in a surface layer, which is UV reflective or absorbing, inhibiting or delaying the curing process. A “slice” may be convenient shaped surface for interface processing—examples being points, lines, planar, spherical or cylindrical, or arbitrary shapes composed of more elementary slices like the former. The thickness or size of the slice may be determined by the absorption depths of the energy or energy density needed to process the base material into the finished material.

b) MIP of Materials—Inner Process Layer/Volume, Moving or Expanding Outwards to the Workpiece Surface Case

The disclosed method includes slice or layer processing which can be used on soft, gel or liquid materials to be processed. In one embodiment of the method, energy is supplied first into the interior of the workpiece with an array of fine delivery probes or energy focal points, arranged to be: i) consistent with the shape of the finished workpiece, and then controllably withdrawn so that the processing volume moves methodically to the surface of the workpiece; ii) the focal points or delivery probes are arranged as a planes or tiles of a closed surface inside the workpiece, which are then moved outward to the surface. For illustration, a “toy” example would be a spherical workpiece. A small spherical region in the center of the spherical workpiece could receive the first processing energy, and then an expanding spherical shell of processing would proceed, with the process energy growing with the square of the distance to the initial process start. In one embodiment of this is when UV, thermal, chemical, microwave, x-ray, electric current or other energy are needed to cure/process soft/viscous/liquid materials, but the cured the material decreases the transport of energy to underlying unprocessed material. As a specific example, some materials become opaque to the UV when cured by UV. If UV flood-illuminated from the surface, a workpiece has a cured surface layer which stops or inhibits the curing of the bulk. Instead, a soft or liquid material could be cured beyond the surface layer by, for example, immersing the energy curing source into a workpiece with a volume shape fitted to the shape of the workpiece, and then moving and expanding area of the energy source towards the surface of the workpiece, curing the entire workpiece, rather than just the surface. A UV-cure example might be an array of UV emitting lasers or LED, focused with variable focal lenses towards the center of the workpiece, such that the energy in the unfocussed parts of the beam are less than sufficient for curing. The foci are then decreased and rastering away from the center. X-ray, gamma-ray or particle beam cured workpieces could utilize energy focused similarly. A similar example is an array of UV transmitting optical fibers or capillaries with a chemical hardener inserted into a polymer precursor at various depths to be cured and then withdrawn. For example, a thermally driven process, where a workpiece is normally immersed into a heat source or bath, and the process makes the processed material more thermally insulative, heat energy is injected via an array of conduction probes or array of focal points from focused microwave, electrical, chemical, visible, x-ray, ionizing radiation, IR, or other process energy, and controllably exposed outwards from the interior towards the surface.

c) MIP of Materials—Rastered Small Process Volume Case—The 3D Part Tool

Another embodiment of the disclosed method is similar to 3D additive printing tools. Instead of adding material with a stepped raster to form a part, in the MIP case, a very small volume of processing energy is rastered through the volume of a precursor material, so that the processed material, slice by slice forms the workpiece. This is may be applicable to liquid or very soft volumes of precursor material, where a part would be produced from processing the liquid or slurry into a solid (as in plastic cross-linking or ceramic greenforms or metal sintering preforms), or other material volumes were the unprocessed material precursor could be easily removed (examples: dissolved, thermally chemically removed, or any other processes which do not affect the MIP-processed part). One example would be a volume of liquid precursor—a UV curable liquid plastic or a sintering slurry. A “processing head” of processing energy (often similar to a 3D “print-head” but not for additive deposition; rather for processing energy or technique) device would be rastered through the volume of the liquid, turned on and off where the part needed to be formed by curing/processing rather than by deposition as in present 3D printers. For example, a UV optical fiber with a microlense or diffusor at the far end, and driven with deep UV light that had a sub-mm absorption length in the liquid could form the “pixels” and then slices of a part.

Another embodiment may use a pulsed thermal tip to process ceramic green form slurries into a part. The remaining unprocessed liquid or slurry would be drained off to be used again. Another realization of this would be to deposit a thin layer (a thin film) of precursor material on the bottom of the inside of a processing tank, and the processing head would then solidify the slice of a 3D part. Another thin layer or film of liquid or soft material would be deposited and the process head would repeat for the second slice. The processing head could be a scanning laser, like a laser printer; a capillary or ink-jet like chemical dispenser; a thermal pulse head; electrode(s); or others.

d) Specific High-Use Example of MIP of Materials of the Slice/Layer Processing Case: Controlled Immersion Edge Anodization—(Abbreviated as Edge Anodization, EA)

Edge Anodization is a specific and detailed realization of MIP of Materials, and may be considered Slice/Layer Processing and an Outer Surface Process Section Moving through the Workpiece to a Far Surface. The EA process adapts standard anodization practice to convert any conductive material that is capable of being anodized by a fluid or plasma process entirely or more completely (a much thicker layer of anodized material on the workpiece) into anodized material, in arbitrary shapes, without any remaining unanodized material, except for a vanishingly small area or strip of electrical connection to the workpiece.

MIP EA Summary:

This patent document has shown methods to anodize a metal film on an insulator of arbitrary shapes, and thin plates, sheets or fibers of metal or conductive materials completely, and is one specific realization of the more general technique of Edge Processing. The EA technique can be implemented in several ways. The method demonstrated in practice is shown schematically in FIG. 1. In this process, the conducting workpiece 10 connected to the anode programmable voltage/current supply 14 is methodically and smoothly immersed at controlled speeds into anodizing bath(s) 18 equipped with appropriate cathode(s) 22, starting at the edge of the workpiece furthest from the anode connection, and being moved methodically towards the farthest edge (the edge where the anode is connected), resulting in complete conversion to oxide, except for a vanishingly small or insignificant metal or conductive edge where the anode voltage is connected to the workpiece, that is designed to be removed or discarded at the end of the EA process. This process works on any anodizable metal/conductive/semiconductive films deposited on arbitrarily shaped substrate materials. Often the metal oxide (or fluoride, chloride, etc.) thus produced is transparent, with high mechanical hardness, or highly nanoporous, depending on anodization conditions. This method can also be used to control the currents on the sample surface by limiting the area of conductive material presented to the electrolyte in the anodization process.

MIP EA Application Summary:

The disclosed method can be used in many applications of the MIP EA process. Some applications include: a) EA-applied scratch-resistant transparent films for glazing, windows, or lenses, either sealed, and/or filled with optical materials for haze reduction or for index of refraction matching, and/or filled with transparent materials for enhanced adhesion to substrates; b) Highly porous or nanostructured surfaces for functionalization including chemical, magnetic, electronic, optical or others, where the pores or structures must have access to and terminate on the underlying substrate. Realizations include filling the pores with scintillation materials for ionizing radiation imaging where the underlying substrate is an imaging VLSI chip; c) Low indices of refraction films which can be used for optical fiber claddings or anti-reflection films, either filled/post processed, sealed, or left open; d) Filters: nanoporous and uniform-porosity distribution; e) Z-axis Conductor/Connector on the micro-scale, where pores are filled with conducting metal, essentially nanowires in the “z-direction”. The resistance parallel to the surface (x,y) is insulative because of the oxide walls, whereas the resistance perpendicular (z-direction) is typical of metals. Such a z-axis connector may be used to connect 2 planar microelectronic chips, or to supply power or cooling to areas of an electronic chip. f) Low dielectric constant layer substrates, near that of air, insulating, for high speed strip-lines or lowering the capacitive coupling of the lines on chips. g) Printing—inkjet printing (ink or others—deposition of small quantities in a spatial order) into the highly anisotropic pores of an anodized film makes an image without ink spreading. h) Scintillator, phosphors or other light-emitting/luminescent materials, including electroluminescent materials into the pores. i) Drugs or chemicals in precise dosages and as 2D arrays. j) Precise binary or more mixture precursor, where alternating pores or pore areas, or in alternating films are filled with 2 or more substances which subsequently are forced together to form a highly uniform compound without extensive mixing. k) Magnetic materials filled in the pores to form highly anisotropic magnetic films N-S orientations l) Hydro-philic or -phobic coatings, especially useful for hard coatings on window materials exposed to the weather or other environmental factors. m) If the anodic film is used in optical applications, the pores can be loaded with transparent, colored or opaque materials, either uniformly, or patterns to: i) reduce haze, ii) adjust the index of refraction, iii) create polarizing effects, iv) create dichroic filters or bandpasses; v) create optical gratings; vi) create patterned optical pathways. Materials absorbing or transmitting specified wavelengths of light can be used in the pores for filters or other optical effects. Highly absorbing films deposited on the walls of the pores create a material that passes light over a narrow range of angles of incidence, the maximum angle θ to the surface being given approximately by sin θ˜(pore diameter/pore length).

The disclosed method can be used to anodize many conductive materials (normally metals) completely (that is, no remaining unanodized material in the workpiece), or with greater anodized layer thicknesses, than those obtained with standard anodizing, by controlled edge immersion into anodizing cells. In this method the workpiece is methodically immersed at controlled speeds into anodizing baths, starting at the edge of the workpiece furthest from the anode connection, resulting in complete conversion to oxide (or fluoride, etc.), except for a vanishingly small or insignificant Edge where the anode voltage is connected to the workpiece. This controlled immersion process also works on any anodizable metal/conductive films deposited on arbitrarily shaped substrate materials (normally substrates unaffected by the anodization process), wherein the deposited metal or semimetal film is anodized completely or more completely, with no or little remaining unanodized material remaining on the substrate except for a connection strip to the anode. Often the metal oxide (or fluoride, chloride, etc.) thus produced is transparent, with high mechanical hardness, and highly nanoporous, depending on the anodization conditions (chemistry, voltage, temperature). A thin metal piece (i.e. foils or sheets) or a metal film on an insulator, such as plastic or glass, is mounted on a motorized stage, which allows the sample to be lowered into the anodization bath at a controlled velocity. The key idea is that the section of the piece just above the anodization bath acts as the anode terminal connection, an edge connection equal at all parts of the cross-section through the thickness of the aluminum piece. As the piece is “adiabatically” lowered into the bath, in effect the anode terminal is presented equally to all parts of the unanodized metal in the bath, unlike the situation if the anodization starts on a fully immersed film, where metal not in direct contact with the electrolyte becomes insulated by the barrier oxide formed on the metal surrounding it. Only the thin strip of (semi-)metal which is just below the bath surface is unanodized, but connected to the same potential. The entire metal is thus able to be anodized as the metal is immersed methodically into the electrolyte. We call this the Edge Anodization technique, and it is shown schematically in FIG. 1.

FIG. 1 is a schematic view of the MIP EA technique where aluminum pieces 10 are controllably submerged into the anodization bath 18, typically by a stepper motor 26. The cathode connection to the electrolyte (anodization bath) is represented by the thick electrode 22, which may be a lead or carbon sheet.

The key technical and scientific challenge is to provide control of the insertion motion and direction to anodize the film with uniform quality. This motion can be controlled with feedback on the anodization current or current density.

There are several constraints on the sample velocity. If the velocity is set too high, then the cell current/voltage (I/V) characteristic will be dominated by the current drawn as the virgin metal surface develops its oxide barrier. In the limiting case of high velocity, it is the same as anodizing the entire surface at once. If the velocity is too low, then the quality of the metal surface and the electrolyte/metal interface will determine the quality of the anodized film. Extremely low velocities and unclean surfaces could lead to unanodized areas of the aluminum surface. Typical velocities are ˜0.1-1 mm/s. Larger or smaller velocities are possible depending on the processing protocol, Al thickness, or the desired pore sizes.

FIG. 2 is a schematic illustration of anodization cell resistance. Note the three distinct regions 30, 34, 38 on the sample representing the three stages of anodization. The physics behind the new MIP Edge Anodization technique (EA) is shown in FIG. 2. As the aluminum piece 10 is lowered into the bath 18, the resistance may be modeled as a parallel network of resistors. There are three distinct regions in the bath that characterize the resistor network. The first region 30 is near the bath surface 42. This region will have the lowest resistance because new aluminum surface is constantly being introduced into the electrolyte. In fact, the only appreciable resistance presented by this region is the resistance of the native oxide present on the aluminum surface. The second region 34 lies below the bath surface 42 where the initial solid “oxide” (for example Al₂O₃) barrier layer 46 has formed. This region will present the highest resistance in the cell for the thin layer anodization because this is where the low conductance oxide is thickest. The third region 38 is the porous alumina region which will have a resistance intermediate to the top two regions because the barrier oxide 50 at the bottom of the pores is thinner than the oxide in the second region. As the sample is lowered into the bath the size of the first region 30 will remain unchanged. The velocity of the sample entry will determine the size of the other two regions 34, 38. Higher velocities will allow the solid barrier region 46 to be larger since we have determined that a finite time is required for the initial oxide barrier to reach its maximum thickness. The higher the initial velocity of the sample, the larger this region will become because more of the sample will be introduced during the period of time required for the barrier to reach maximum thickness. Conversely, lower velocities will result in a smaller solid barrier region 46.

To first order, the size of the porous region 50 will depend on the overall size of the area to be anodized. Large area samples will inevitably have a porous region develop near the leading edge of the sample first introduced into the bath. The area of this region is also dependent on the sample velocity v to second order, since the area of this region (width w) is the area of the entire submerged portion of the sample A_submerged (=vtw) less the first and second regions. That is, the porous area A_porous for long times t:

A_porous=A_submerged−A_interface−A_barrier   (1)

or, by substituting the size A of the other regions

A_porous=vtw−vt_reqw−A_barrier   (2)

where v is the velocity, w is the sample width at the electrolyte surface, and t_req is the time required for the initial oxide (or fluoride, etc.) barrier area A_barrier to reach its maximum thickness.

Anodization chemistry is commonly available for Al, Ti, Mg, Ni, Zr, and Zn, with Fe alloys less commonly used (black ferric oxide). Many standard anodization methods are described in ASTM standards. Fluoriding and similar chemistry beyond oxiding are also applicable to Edge Anodization. Titanium (oxide), Aluminum (oxide) and Magnesium (fluoride) Edge Anodization are particularly useful applications.

MIP Edge Anodization (EA) of Aluminum will be discussed further below. A pure Al foil can be entirely anodized into a form of transparent alumina. An Al film deposited on a non-conducting substrate, such as glass or plastic, can be entirely anodized into a transparent, hard, highly scratch resistant form of aluminum-oxide, capable of being fabricated as largely porous, with a monotonous array of nano pores and porosities that may exceed 65%. FIGS. 10-14 show the nanoporous film properties of EA processed Aluminum. FIGS. 15-18 show photographs of the Edge Anodized pieces of deposited films, and of a common kitchen Al foil. These nanopores can be widened, sealed, and/or filled with other materials to enhance its properties for desired characteristics, for example for moisture sealing of the anodized film as a scratch-resistant plastic or glass. When sealed as full of air or other low index materials, alumina nanoporous films may have an index of refraction n lower than that of any common solid optical fiber cladding film, approaching n=1.1 or even below, and adjustable up to or exceeding that of sapphire with appropriate loading of the nanopores.

Below is discussed anodized aluminum and the formation of alumina and sapphire-like films. The anodization of aluminum is a large subject, however, in general, aluminum anodizes to form a porous film of amorphous (non-crystalline) phases alumina (boehmite, γ-alumina—Al₂O₃) on the aluminum. The film is composed of essentially the same materials-base as sapphire and alumina ceramics. These materials are among the most intrinsically hard known, and are also transparent. Remarkably, the size of the resulting porous structure is essentially unchanged from the parent aluminum. Aluminum is not removed—the incorporation of oxygen during anodization produces a molecular structure smaller than the original aluminum, thereby providing the driving mechanism to create pores in the anodized aluminum. Microporous alumina (Al₂O₃) thin sheets or films exhibit a highly anisotropic and uniform pore structure consisting of channels perpendicular to the film surface, whose size and spatial distribution can be controlled by changes in the anodization process parameters The channel position is quasi-regular, on a quasi-regular hexagonal matrix. The areal density, size and regularity of these pores is controllable over a remarkably wide range with the electrolyte chemistry, temperature, current density, and the electric field during the anodization. The pores typically range in size from about 5 nm to about 200 nm in size, and vary in areal open pore density from about <1% of the alumina surface up to about 65%. The pores terminate in a non-porous thin boundary layer of alumina at the aluminum alumina interface, the thickness of which is also determined by the anodization conditions. These porous structures have wide application in technology (filters for example), and are the basis of colored anodized aluminum by incorporation of dyes into the pores. The remaining underlying Al metal of must be mechanically or chemically removed depending on the application. FIG. 3 shows a schematic of the standard anodization process, as it will also be applied to Edge Anodization as in FIGS. 1, 2.

FIGS. 1 and 2 show the Edge Anodization method for how to move the strike-layer from the whole Al surface to one edge, so that the entire Al remains connected except for a thin stripe or area at one edge of the work piece when the process terminates.

As shown in FIG. 3, when aluminum is anodically oxidized in an acidic electrolyte, a uniform and oriented porous structure may be formed with nearly parallel pores organized in a hexagonal geometry. By adjusting the anodization voltage, electrolyte composition, and concentration, one can accurately control the diameter and center-to-center spacing of the pores. A post-anodization pore widening step using phosphoric acid allows further control of the pore diameter.

FIGS. 9 shows SEM images from the literature showing the variation in pores by variations in standard prior art Al anodizing process parameters. FIG. 4 shows a thin porous anodic alumina films with self-ordered cylindrical vertical pores in aluminum films deposited on a substrate, Note the film thicknesses; FIG. 8 shows the high density of pores possible; FIG. 9 shows the results of pore-widening in Aluminum to alumina anodization using standard techniques.

All these films result in a barrier layer and opaque strike layer left behind as in FIG. 3. These pores can be extended so that no strike or barrier layer remains, using Edge Anodization process.

In some embodiments, MIP EA technique can be used to obtain complete anodization of aluminum on glass or lucite, with sputtered Al and with evaporated aluminum films, varying from about 0.5 to about 4 μm thick, roughly following the schematic of FIGS. 1, 2. A fast-responding linear stepper motor was programmed with step size of 50-100 nm and step period/rep rate to achieve speeds of 0.1-1 mm/s to insert the slide into an anodization bath, starting from the bottom, and a programmable power supply was programmed with a current profile. In some embodiments, the step speed varied between 0.1-0.3 mm/s.

In some embodiments, the MIP Edge Anodization electrolytes for Al were aqueous solutions of sulfuric, chromic, phosphoric or oxalic acid (typically about 1% to about 30%). In some embodiments, solutions were used of phosphoric, sulfuric and oxalic acids at concentrations of about 2% to about 20%. In some embodiments, typical cell voltages ranged from about ±10 to about ±150 volts. Typical stepper profiles ranged between about 0.1 to about 0.5 mm/s. Anodization cells consisted of a pair of about 5 cm× about 5 cm× about 1 cm thick graphite or lead cathode electrodes connected by teflon or poly insulated wire, immersed in teflon or polyethylene or other containers resistant to the anodizing acids. Sets of anodizing cell containers were maintained to avoid contamination amongst electrolytes. The graphite and lead electrodes were obtained with highly polished surfaces (stainless steel is also appropriate). The leads were attached in blind holes with silver paint and protected with fluorocarbon grommets. A set of gauge blocks of machined plastics maintained the cell electrodes highly parallel. Electrode separations were adjustable from about 0.5 mm to about 1 cm. The power supplies operated either under constant current and constant voltage regulation using a highly regulated power supply with a voltage range from about ±0 to about ±300 Volts which can supply up to about 10 A. The temperature was controlled and measured to about ±0.5 C, over a range from about 0° to about 80° C. The films and foils were chemically etched, rinsed and briefly vacuum dried at moderate temperatures before anodizing. Samples of the pores produced are shown in FIGS. 10 and 11 below.

FIGS. 10 and 11 are figures showing the scanning electron microscope (SEM) micrographs of Anodic alumina formed by MIP Edge Anodization. FIG. 10 is a film produced from Al film on glass, before pore-widening. FIG. 11 is a 2 μm×2 μm square SEM field formed under different anodizing conditions. The pores are ˜50 nm, <optical wavelengths. These films were transparent, with no strike layer left.

A study was performed on the MIP Edge Anodization of aluminum to optimize the anodization conditions needed to produce a matrix of uniformly sized and spaced pores. The effects of varying anodization voltage, temperature, time, electrode geometry, and the composition of the anodization bath were examined. Samples were anodized using a DC current and a nickel mesh as the cathode material with 3″ or 10″ spacings. The DC anodization voltage was varied from 20 to 200 volts and anodization times ranged from 5 minutes to 4 hours. Electrolytic solutions of 0.5, 0.3, and 0.05 weight percent oxalic acid and 0.3-weight percent phosphoric acid were used in the anodization baths, which were typically kept at 5° C. After anodizing, many samples were pore widened in 0.5 weight percent phosphoric acid at 37° C. Almost all of the samples were oxidized in air at 150 C for 30 minutes prior to anodization.

Using SEM and photomicrographic data, and different deposited Al film starting thickness, it was confirmed that the pore depth for the edge anodization is a direct function of edge anodization time, as it is for standard Al anodization. The size and spacing of the channels are very uniformly distributed, and they form a closed packed hexagonal array of columnar cells.

FIG. 12 is a plot showing the dependence of the pore size on anodization voltage using a 2 wt. % oxalic acid electrolyte. A typical fit to the dependence of anodic alumina pore cell diameter on anodization voltage under the same chemistry and temperature obtained in our studies.

It was determined that the pore diameter and center-to-center spacing were close to independent of anodization time. The anodization time does, however, determine the depth of the pores directly. The pore size and spacing are a function of voltage, with the diameter also depending on whether the pores were widened in phosphoric acid or not. FIGS. 10, 11, 12 show the voltage dependence of the pore diameter and spacing, respectively. The data are both fairly linear, with some of the spread being attributed to not distinguishing between the 3″ electrode spacing, the 10″ electrode spacing. Linear best fits are presented for FIGS. 13 and 14, respectively, showing a dependence of the pore size d, d∝0.5 V_A, and pore spacing s, s∝V_A, where V_A is the anodization voltage, and d and s are in nm.

FIG. 13 is a plot that shows the pore diameter as a function of anodization voltage for the samples studied. The data has been sorted according to electrolyte (OX=Oxalic Acid; Phos.=Phosphoric Acid), weight percent, and pore widening (PW). The data is roughly linear with a little spread, because this plot does not distinguish data taken at a 3″ electrode distance, or 10″ spacing.

FIG. 14 is a plot that shows the center-to-center pore spacing as a function of anodization voltage for the samples studied. The data is roughly linear with a little spread. Pore widening does not affect pore spacing.

FIG. 15 shows a photograph of an early test of an aluminized slide after anodization, and back and third from the bottom reflect the stepper step size and anodization and insertion speed not optimal for complete anodization. FIG. 16 shows the results of refined programming of the EA rig, showing nearly complete anodization in six (6) regions of different EA conditions—the boundaries of some regions are nearly invisible. The transparent hard films appeared to be highly scratch resistant with metal tools, and required a carbide scribe. At some larger thicknesses, colored interference fringes were evident. FIG. 17 shows a photograph of a normally illuminated glass slide with 4 edge anodizations. The best anodization is close to the transparency of normal glass, and was formed by Oxalic acid 0.5%, 100V and 200 μm/s.

FIG. 15 is a back-illuminated (on a light box) photograph of an aluminized and then edge anodized slide in early tests of edge anodization technique (EA), in 3 regions starting from the bottom. The 4th top region shows the opaque unanodized aluminum film used as the edge anode contact, as in FIG. 2. The region second from the bottom (labeled with hand drawn “#2”) demonstrates nearly complete anodization but shows that the stepper is not being run smoothly enough. Regions 1 and 3 were anodized with rates and currents which left larger and more numerous islands of aluminum unconverted to alumina. The wavy aluminum lines are due mainly to the unstable creep of the meniscus (or wetting line) as the work piece is inserted into the electrolyte anodization bath. FIG. 16 is photograph of a back-illuminated (resting on a light box) aluminized slide in tests of complete edge anodization (ET), in 6 regions with different current density and insertion rates, starting from the bottom. The top region shows the opaque unanodized aluminum film used as the edge anode contact, as in FIG. 2. Nearly all of the aluminum below it was converted to transparent alumina. At 4 of the boundaries between regions where the stepper changes speed and the current is changes, some aluminum lines are left. A hardened steel scribe did not scratch these surfaces, whereas a carbide scribe scratched. FIG. 17 is a photograph of a normally illuminated glass slide with 4 edge anodizations. The best anodization is close to the transparency of normal glass.

FIG. 18 shows a photograph of a free-standing alumina film created by edge anodization of a standard aluminum foil about 50 microns or μm 10¼^t thick obtained from a local supermarket. It was anodized completely over a length of about 2.5 cm from the far end. To demonstrate its flexibility and clarity, it was bent or curled to rest conformally against a curled dollar bill and flash photographed. George Washington's face is clearly seen through the anodized foil end.

FIG. 18 is a photograph of a George Washington's head on a dollar bill through a piece of free-standing alumina film, created from a strip of aluminum foil about 4 cm wide and ˜10 cm long. The clear anodized film area is about 2.5 cm long by about 3 cm wide starting at the edge of George Washington's face, covering his whole face and neck. The unanodized aluminum strip attached to it blocks an area and may be about 5 cm by about 3 cm starting at the right shoulder of the president and nicking the oval surrounding the “1” in the lower left of the picture. A pen and ruler are included for scale. Such an immersion technique can be made to work on very large sizes provided: (i) if an Al, Mg or other metal film is required on the workpiece, that a sufficiently large aluminization apparatus is obtained—for example bell jars are common for plastic or glass glazing at least in sizes of 4′×8′ and even larger; and (ii) a sufficiently large anodization bath (i.e. pool) is obtained in which to edge immerse a large work piece. Such pools are common in the automotive, marine and metals industries in general.

Brief Summary of Preferred Embodiments of MIP-EA

How MIP-Based Edge Anodization (EA) is an Improvement

Almost all other anodic processes produce an insulating oxide (or other, such as fluoride or sulfide, etc.) insulative barrier layer that terminates the anodization from proceeding to greater depths into the material being anodized. A major issue of anodizing is achieving sufficient thickness of the anodized part, or bonding the anodized film on the surface of the workpiece. Typically, anodized films are at most about few microns thick. The workpiece is also opaque, since underneath the normally transparent oxide barrier layer is opaque metal or semi-metal. The anodized films formed using Edge Anodization can be made to greater thicknesses, and up to complete anodization of the workpiece. For example, normal anodizing of aluminum leaves aluminum underneath the alumina, and the alumina layer has a finite thickness determined by and limited by the anodization process and resistivity of the alumina, and may not be made thicker, often less than a few microns, and the workpiece remains opaque. In another example, other methods of forming transparent hard coatings on plastic, glass or other relatively low temperature materials can be limited by the temperatures needed to form such materials, or by relatively lower hardness of deposited scratch-protective coatings. Most other methods to form hard and low index of refraction films are far more costly than the Edge Anodization method described above. Adhesion of or compatibility with other types of films as deposited on substrates is often limited, especially by internal stresses and thermal expansion mismatches, or by environments needed or by other mismatched processes.

Items or Steps that Make Up the MIP EA of Materials Process Invention.
a. Pre-Processing:

In some cases, the workpiece may require or benefit from pre-processing before the Edge Anodization process. (a) Ordered Pores: One such case is to obtain exceptionally ordered pores in porous anodized material, where the pores are initiated by patterned depositions or physical indentation or other pore initiating strategies. (b) Patterning of the Edge Process on a workpiece: Pre-processes may protect specified areas of the workpiece from anodization, by application of protective films, or by counter-electrical connections which prevent anodization in specific regions, or by deposition in specific regions of the material to be anodized, with connections to each region along the direction of Edge Immersion. Such cases include applications in micro/nano electronic or photonic integrated devices. (c) Adhesion and Stress Mismatch: Another such case is to enhance adhesion of an anodic or Edge Processed film/material formed on a substrate if there is thermal mismatch, stress at the EP film—substrate interface after anodization, or non-conformal issues with the edge Processed material. The metal to be anodized (or other material in Edge-like Processing) is divided by sufficiently fine mesh lines into separated patches sufficiently small that the processed material mismatch is minimal (typically hexagonal, triangular or square/rectangular surface tiling). The patches remain connected by fine “bridges” (in anodization for example by electrically conductive bridges) in the direction of the Edge Processing. For example in metal anodization the patches are connected by fine metal bridges of the same material or non-anodizing conducting materials so that these anodic “islands” covering the substrate except for the fine lines separating them are formed with stress only over the area of an island and not accumulated over the much larger area of the whole workpiece, analogous to the thermal expansion joints in civil construction. Such patterning could be done by removal after uniform coating (example: a laser which scribes out a patch except for the bridge(s)), or by initial deposition patterning, or by secondary patterning of the fine lines with a resist that prevents the Edge Processing on fine lines which separate the patches. FIG. 24 shows a schematic of stress relieving method described in this paragraph. Sheets of aluminum 50 may be attached to each other by thin bridges 54 of material. Each of the bridges may be about 0.05 micrometers in width and about 0.1 micrometers in length. The dimensions of the sheets of Al 50 may be about a few micrometers per side. An anodization fluid bath 58 is shown.

b. MIP Anode Edge Anodization Connection and Immersion Direction:

This step is the determination of anode connection(s) position(s) on a sufficiently conductive material to be anodized, that will leave a vanishingly small or unimportant unanodized area (the Edge) at the termination of the Edge Immersion Anodization process, that can be removed or discarded at the end of systematically immersing the edge-anode-connected workpiece cross-section/area most distant from the Edge, until the Edge contacts with the anodizing fluid. The current flows through the gradually immersing workpiece, typically 0.1-1 mm/s but depending on current, voltage and chemistry, to the Edge connection. When immersed in a specified direction (the Edge Immersion direction) into the anodizing fluid at a controlled speed, voltage, chemistry, temperature, and current density, the entire workpiece is able to be anodize—the metal or conducting material completely removed, leaving the boundary layer in the case of porous anodization.

c. Electrical Connection and Anode Power Electronic Properties:

The next step may be the connection of the workpiece at the anode connection(s) in Step 1 to programmable bipolar anode power supply(ies) of sufficient voltage (±1-300V), polarity, current density (a few mA−few A/cm²), impedance (typically 1-15 Ohms), power density (0.1 W-10 W/cm²), and temporal profile programming so that the anodizing rate and properties are controllable as a function of time during the Edge immersion of the workpiece.

d. Chemistry and Cathodic Connections:

The next step may be the adjustment of the chemistry of the anodizing bath(s) in anodizing tank(s) to achieve the desired anodization properties of the workpiece material. Anodization chemistry is commonly available for Al, Ti, Mg, Ni, Ti Zr, and Zn, with Fe alloys less commonly used (black ferric oxide). Many standard anodization methods are described in ASTM standards. Titanium and Aluminum Edge Anodization are particularly useful applications. Typical anodization baths include chromic, sulfuric, oxalic or phosphoric acids. The Chemistry conditions to create highly ordered nanopores in aluminum films completely Edge Anodized to alumina are an important application of this invention. Borate or Tartrate anodization solutions for Al are of particular interest in methodical Edge Immersion Anodization because they do not dissolve resulting alumina barrier layer, in applications of the process where that would be important. Nanoporous/structured oxides are often produced with other materials systems. In one example, when anodized in an about 0.5 weight percent HF solution for about 20 minutes, titanium forms well-aligned titanium oxide nanotube arrays with an average tube diameter of 60 nm and length of 250 nm. The Edge anodization technique will enable arbitrarily deeper films of titanium oxide, without any remaining titanium. In Edge Anodization, pores formed at the leading edge of the work-piece may be deeper than those formed near the solution interface because they are exposed to the low pH electrolyte longer, and may this etch. To mitigate this effect, the chemistry or concentrations of the anodizing fluid(s) may be adjusted as a function of time and/or spatial gradients along the direction of the Edge Immersion and may be introduced by a variety of methods. Among many examples, some are listed below, as (a) through (f). (a). A temporal chemistry gradient could be obtained by injection of different anodizing fluids over the anodizing cycle. (b). Spatial gradients in concentration or chemistry could be obtained with multiple injected anodizing fluid flows into the tank as a function of position along the edge immersion direction. (c). An example of a step-gradient in chemistry is by separation of regions with physical barriers between fluid regions along the Edge-Immersion direction, with flexible flap-like apertures between the regions which are as conformal as feasible to the cross section of the workpiece being edge-immersed to pass through, thus separating anodization chemistry regions; the fluid in each region can be continuously refreshed. (d). As another example of a very simple spatial gradient of chemistry, a continuous or very long flexible workpiece, such as aluminized optical or other fibers or flexible sheets, could be Edge Immersed, but bent into a curve so as to re-emerge from the anodizing bath into air or to be inserted into a stop-bath or post-processing regions, so that the entire workpiece can be anodized uniformly in a continuous process. This is particularly apt for fibers or ribbons, for example to make optical fibers with a very low index of refraction, or to coat flexible glass or plastic ribbons with scratch-resistance anodized metals. (e) A plurality of cathode connections may be included over different spatial concentration or chemical regions which may be at different cathodic voltages, as supplied from individual bipolar programmable power supplies over the anodizing cycle(s). (f). If the pores are formed too early, at the start of the process, and begin to become too large or dissolve, the piece can periodically be withdrawn after a set distance of immersion and the pores protected from the anodization bath by a spin-on polymer or similar protective film, which could then be stripped off after full processing. The piece would then be re-immersed to the edge of the protected region (i.e. back to the bare aluminum film) and the edge anodization continued.

e. Temperature:

In the process there should be control of the temperature and temperature temporal or spatial gradients of the anodizing bath between the lowest and highest temperatures (typical practical ranges are about 0° C. to about 100° C. but can be higher or lower), sufficiently accurately, which may be as fine as about ±0.5° C. or finer, with controllable time dependence which may be as fine as sub-1s scales. A temperature spatial gradient in the anodizing tank along the Edge Immersion direction can be specified to affect the pore growth speed or pore spacing an uniformity, for example to ensure uniform (typically lower temperatures near 0° C.) or other controlled anodizing, similar to the effects of a gradient in voltage or chemistry as in the steps above. Such a gradient can be obtained with a plurality of temporal programmable heaters/coolers or fluid injectors along the Edge Immersion direction.

f. Rates/Speeds and Directions of Edge Anodization Immersion:

Edge Immersion into the anodizing bath may be programmed at a rate such that the material to be anodized is either completely anodized, anodized to a specific depth, or completely anodized to an underlying workpiece/substrate, with controlled uniformity or depth, but not so that the anodized material is dissolved away by the end of the process cycle. This may be achieved, for example, by a programmable linear stepper motor, or any other robotic or carefully controlled methods to control the motion of the workpiece's Edge Immersion into the anodizing bath, preserving the connection to the anode outside of the bath until the last edge of the workpiece is immersed in the anodizing fluid. This last thin piece of material is the Edge connection, and is normally removed from the finished Edge-Anodized workpiece. Alternatively, the workpiece could also be gradually exposed to the anodizing bath by controlled removal in a specified Edge Anodization direction of a material protecting the workpiece from the anodizing fluid(s). Such material could be a physical sleeve which is withdrawn, a chemically, thermally or electrically removable coating, or others. In the most basic case, that protective material is the air above the anodizing bath, as the workpiece is methodically Edge Immersed vertically into the anodizing bath.

As an example, in a realization of anodizing 1-10 micron thick Al films deposited on plastic or glass substrates, the speed of vertical immersion in a fairly standard oxalic acid anodizing bath varies between about 0.1 mm/second to about 1 mm/second to achieve highly transparent films.

Another example (as also described above), is a fiber or flexible sheet being Edge Anodized could be curved to emerge from the anodization bath so that further anodization or dissolution does not take place, or to be fed through a flexible aperture into a region that quenches the anodization or further treats the workpiece. FIG. 25 shows an example of the flexible sheet being edge anodized. In this example a flexible sheet of material 60 is moved along rollers 64 through an anodizing bath 68, out of the anodizing bath 68, and into a post processing fluid bath or quench bath 72, and then out of the bath 72.

One characteristic of the immersion technique is that the pores formed at the leading edge of the work-piece will generally be deeper than those formed near the solution interface because they are exposed to the low pH electrolyte longer, and etch. In one realization, if the pores at the start begin to become too large, the piece can periodically be withdrawn after a set distance of immersion and the pores protected from the anodization bath by a spin-on polymer which could then be stripped off after full processing. The piece would then be re-immersed to the edge of the protected region (i.e. back to the bare aluminum film) and anodization continued.

g. Pore Widening or Sealing:

If desired, a pore-widening step may be included in the process where pores result from the anodization. This may be accomplished by chemical baths or any other processes which (normally isotropically) removes the anodized film. In the case of porous alumina, phosphoric acid solutions are often used. In alumina, a thermal steam oxidation or aqueous heating can seal the pores.

h. Pore Functionalization Steps:

If desired in a porous anodization, especially those that terminate on an underlying substrate used in the part being made, a pore loading or sealing step may be included, or other functionalization, such as hydro-phobic or -philic, index of refraction, patterning or other functionalization by deposition, removal or patterning. Pore loading may be accomplished by many film or material deposition techniques from solids, liquids, gases or plasmas, including MBE, CVD or ALD or other similar conformal or filling processes.

Precursors Necessary to Realize the MIP EA of Materials Process

Many standard anodization (oxiding) process and materials system can be adapted and tuned (as described in the realizations above: chemistry concentrations, voltage, current density, temperature and immersion speed) to Edge Immersion Anodization of Al to form the properties needed in the resulting edge immersed anodic alumina film. Similarly processes for more generalized edge anodization, such as fluoriding, chloriding and others are possible by adapting anodization processes from standard the anodization process details—for example, aluminum, magnesium, and nickel fluoride films can be by obtained by anodization, and hence Edge Immersion Anodization can convert the entire sample to fluorides, in this example.

In one specific and useful realization, the requirements to perform the Edge Anodization process is anodizing completely an aluminum film, about 5 to 10 μm thick, deposited on an insulating substrate such as plastic or glass workpiece, in which the anodic films becomes transparent, hard, and/or nanoporous, are shown in the numbered list below. Conditions such as electrolyte concentration, acidity, solution temperature, and current must be controlled to allow the formation of a consistent oxide layer. Harder, thicker alumina films tend to be produced by more dilute solutions at lower temperatures with higher voltages and currents. The alumina film thickness can range from under about 0.5 μm to about 150 μm in standard anodizations, but with a remaining boundary layer and aluminum.

• • 1. A reasonably pure Al film—99.99% or better Al.
  • 2. A bi-polar power supply capable of ±150V or more.
  • 3. Most standard aluminum anodizing baths, usually acid-based, such as oxalic (0.1—a few wt %) or sulfuric acid similar to battery acid concentrations, but with low contaminates.
  • 4. An anodizing bath vessel, usually of an inert plastic, with an cathode, typically Pb or other chemically resistant metal, with appropriate fluid heater or cooler exchangers.
  • 5. Thermal measurement controls of the bath, and agitation/mixing of the bath.
  • 6. A motor (linear stepper motor or other) capable of sub-micron linear motion, over a distance a least as long as the workpiece, with a programmable controller capable of ˜(sub)millisecond or finer steps, installed appropriately on or above the anodizing vessel.
  • 7. Chemical cleaning/rinsing baths, etching/rinsing baths, de-Ox/rinse baths of workpiece (standard anodizing processes), to present bare metal to the Edge Anodization process.
  • 8. Mount of workpiece to insertion stepper, power supply connection to the Edge Anode, and cathode.
  • 9. Programmed process parameters Temperature, Time, Velocity and Voltage, and Edge Immersion insertion.
  • 10. Post-rinse bath.
  • 11. Post Processing such pore sealing, pore filling, or others as needed.

General MIP of Materials Embodiments—I

a) MIP of Materials—The Slice/Layer Processing Case—An Outer Surface Process Section Moving Through the Workpiece to a Far Surface

This materials modification process is the technique of supplying a surface, edge, layer, or restricted volume of a workpiece to some source of process energy or process technique that is used to modify the material of the workpiece, starting from a specific place on the surface of the workpiece, and moving that process surface methodically through the workpiece. Normally a planar slice of the workpiece is envisioned where the processing is taking place, but in principle the slice could be any surface shape. At controlled rates of speed and of process energy density delivery, the workpiece is methodically exposed to process energy or processing, starting from one surface, edge, layer or restricted volume of the workpiece, rather than the entire workpiece at once, with the processing restricted to a surface or small volume, slice by slice. That processing surface or volume or layer or “slice” then moved through the entire volume of the workpiece to the unprocessed regions, controlled so that the entire workpiece is uniformly processed. The motion of the energy or process technique exposure is directed away from the original layer, surface or edge, until the entire workpiece has been processed.

This moving surface process is useful in cases of materials modification processes such that if a three-dimensional workpiece were otherwise fully exposed to the process or process energy source on its entire outer surface, the resulting processed surface layer would self-limit the energy/processing delivery into the bulk of the workpiece, and so the entire bulk is not processed; rather, just a surface layer is processed which prevents or slows further processing of the bulk.

In one example, metal anodization almost always self-limits anodization of the entire workpiece, as it creates an insulating barrier film, so that immersion of a metal workpiece into an anodizing bath only anodizes a surface film and not the entire metal. The specific application of this is Edge Anodization (EA) in this example will avoid this problem of self-limited anodization.

Another example is a thermally driven process, where a workpiece is normally immersed into a heat source or bath, and the process makes the processed material thermally insulative, thus inhibiting the speed of processing. Using the disclosed Edge Anodization technique, heat energy is injected into one edge or layer or “slice” of the workpiece and the slice of injected thermal energy is then controllably moved towards the far edge of the workpiece, enabling a much thicker layer or complete processing of the workpiece to be produced.

In another example, UV curing of plastics can result in a surface layer which is UV reflective or absorbing, inhibiting or delaying the curing process. MIP can overcome this inhibiting or delaying.

MIP—EA Edge Anodization Process and Edge Processing Advantages

Produces thicker anodization layers, wherever anodization is used at present, for example for protecting underlying metal. Edge Anodization enables metallic films on arbitrary shapes or sheets, wires, foils, or other shapes to be completely converted to the oxide (or fluoride, etc.) form. As an example, transparent hard coatings, such as alumina formed on plastic or glass, can be formed from Al deposited on the surface by Edge Anodization, or Mg to MgF2. Edge Anodization processing of other conductive, semi-conductive or semi-insulating materials beyond metals, either as films or bulk. Such material processing includes electro-chemical and photoelectrochemical etching or removal of Si, Ge, II-VI or other semiconductors or carbon-based materials such as diamond. Some forms of EA produce highly porous or nanostructured films (such as nanopillars or wires) which have many applications as discussed below, whether free-standing, or formed on substrates, without the underlying material remaining.

Applications of MIP Edge Anodization (EA)

Some applications include using a thin anodized layer of material on other materials for a transparent scratch resistance surfaces. Such applications would include: plastic or glass glazing, windows and lenses such as acrylic or polycarbonates, softer glass for home and commercial buildings; glass for vehicles or drones; electronic displays such as on cellphones; eye glasses or sunglasses; applications where glass or plastic is used for transparency as a window or lens or protective material. For example, using a plastic window with an anodized layer of material would have only about 40% of the weight of glass, and be nearly unbreakable, and may be cast in nearly arbitrary shapes, such as the bubble-like windscreens of airplanes. The coatings would be from Edge-Anodized aluminum or titanium. The hardness of alumina films varies between about 10 to about 20 GPa, and MOHS between about 7 to about 9. On substrates, the Knoop Microhardness of Al₂O₃ films is about 1,000 kg/mm2. For example, glass used on cellphone displays could be made more scratch-proof (thus decreasing the chance of shattering) or be replaced by similarly coated plastics. Flexible transparent materials such as thin specialized glass films or ribbons or plastic films could be made with highly increased scratch resistance using a MIP Edge Anodized layer of material.

Other applications include general scratch resistant coatings. The coatings may be opaque or not as applied to metals, plastics or other materials. For example, aluminum deposited on other metals (especially metals which resist the Al anode chemistry) could be converted by EA to a hardened thick insulative film capable of very high temperature/refractory operation (unlike plastic insulative films). An example would be metal wires: thin gold film a few nm thick overcoated with, say, about 10 to about 50 μm of Al, could be anodized to form a highly resistive and robust conformal insulator capable of high temperature operation. This could be scaled down to wires or surfaces in VLSI/microelectronics.

Another application would be functionalized coating applications after anodization. Films of porous anodized materials can be pore-loaded or pore coated with materials or treated to produce other properties after the EA process. The methods to fill or coat pores include liquids, doctor-blading soft materials, vacuum deposition techniques, CVD/MOCVD, ALD, MBE or other film technologies from the liquid, slurry, viscous, gas or plasma technologies, like adhesion, or drug-delivery, where completed or near complete pores would be useful.

The disclosed method can be used in filled or coated pore applications. For instance, with respect to printing, such as inkjet printing (ink or others—deposition of small quantities in a spatial order), the highly anisotropic pores of a completely or nearly completely anodized film could make an image without ink spreading as in the case of random porosity or fibrous materials such as paper. A plastic film (white or clear) with an edge anodized Al film top surface would make a very high dynamic-range and high-precision pixel surface for reproduction, down to the 10's of nm scales. The disclosed method can be used for scintillator such as phosphors or other light-emitting/luminescent materials, including electroluminescent.

The disclosed method can also be used with drugs or chemicals in precise dosages; aliquots as a chemical libraries; Magnetic materials, since the anisotropy forms N-S orientations.

In addition, the disclosed method can be used with adhesion and sealing because pores in EA surfaces can be filled with liquid or viscous adhesives, polymers, or other materials which may: a) Seal the pores from the atmosphere or environment; b) Add strength to the pore walls for scratch-resistance. Materials which when solidified or cured by heat, light, radiation or other energetic so that they shrink slightly in the pores to preserve the hard anodic material at the surface; c) Adhesion: if the anodic material is formed on another surface, the pores can be loaded with adhesives to enhance the adhesion of the anodic material to the substrate. d) Sealing of the surface, leaving pores underneath can be obtained by steam oxidation for anodic Al, and for all porous anodic materials by oblique deposition of sealing materials, so that a void is left under the sealed top. Line of sight vacuum deposition at angles to the surface <45°, with periodic rotation will seal the pores leaving >½ the pore depth intact. B7: Hydro-philic or -phobic coatings, especially useful for hard coatings on window materials exposed to the weather or other environmental factors. Hydrophobic films keep sub-micron pores open under rain or immersion conditions.

The disclosed method can be used for precise binary or more mixture precursor, where alternating pores or pore areas, or in alternating films are filled with two or more substances which subsequently are forced together to form a highly uniform compound without extensive mixing.

The disclosed method can also be used to obtain certain optical properties. If the anodic film is used in optical applications, the pores can be loaded with transparent, colored, opaque, neutral density, electro-optic, magneto-optic, or other passive or active materials, either uniformly, or patterns, and either fully filled, partially filled, sealed, or as a thin film on the pore walls. Example of the results include: i) haze reduction, ii) adjust the index of refraction upward, iii) create polarizing effects, iv) create dichroic filters or bandpasses; v) create optical gratings; vi) create patterned optical pathways; vii) anti-reflection films by tuning the index of refraction of the anodic film to the optimal geometric mean index—that is: n1=√nons where no is the index of air, and ns is the index of the anodic film; (viii) Materials absorbing or transmitting specified wavelengths of light can be used in the pores as filled or coated for filters or other optical effects. Highly absorbing films deposited on the walls of the pores create a material that passes light over a narrow range of angles of incidence, the maximum angle θ to the surface being given approximately by sin θ˜(pore diameter/pore length).

The disclosed method may be used with low index of refraction coatings. For instance, Low Index Anodic Material: MgF₂ or other low index of refraction films used for AR (anti-reflection) coating may be produced by edge anodization could be used for (scratch-resistant) low index anti-reflection coating with index n₁. The disclosed method may be used with low index via highly nanoporous anodic films. As an example anodic alumina films have indices of refraction as low as 1.08 due to an air fraction of 65%-75% in the highly porous films, up to the index of the alumina itself n˜1.7. The index can be raised from this value by pore size and spacing, or by filling the pores with relatively low index materials such as Teflon AF. Anti-reflection coatings would result in films by tuning the index of refraction of the anodic film to the optimal geometric mean index—that is: n₁=√n_on_s where n_o is the index of air, and ns is the index of the anodic film. For the example of glass (n_s≈1.5) in air (n_o≈1.0), this optimum refractive index is n₁≈1.23, difficult to obtain. For plastic with n=1.6, n₁≈1.26. In addition, the disclosed method may be used in total internal reflection applications—light guiding and optical fibers. Such films could totally internally reflect light transport in a water core. Normal glass optical fibers cladded with such an Edge-Anodized nanoporous transparent film would have a numerical aperture NA of ≧0.9, and could transmit 3 to 4 times more light than ordinary clad fibers. These would have applications in laser machining, surgery, optical power transmission (especially for tethered drones used in construction or repair industries, or military), drug & chemistry R&D, analog sensors and many other applications. Typical optical fiber performance is shown in the figures below.

FIGS. 19, 20, and 21 show cartoons of light trapping in a plastic scintillating fiber. The angle θ is the trapped cone angle.

FIG. 22 is a photograph that shows a MEMS-fabricated silica fiber with effectively a near-air index of refraction cladding, and an NA≧0.9 If instead of using MEMS, a film of ˜5 microns of Al coated a fiber and were edge anodized, it would result in a nanoporous low-index cladding also closer to air.

The fraction of light piped to each end of a fiber is shown in the cartoon of FIGS. 19, 20, 21. The fraction f piped is given by the cladding n2 and the core n1, the critical angle_α, maximum accepted cone half-angle θ, and the Numerical Aperture NA by:

f=½(1−n₂/n₁)   (4)

sin α=n₂/n₁   (5)

NA=(n₁²−n₂²)^1/2=sin θ  (6)

Typical fractions of light generated in the fiber and trapped per end are f=about 3 to about 4% for single-clad commercial plastic fibers. If the cladding could be made to have an index of 1.2, the fraction trapped would rise to about 12.5%, about tripling or quadrupling the trapped light fraction. A cladding index of 1.4 would double the fraction of trapped light, to about 6 to about 7%, as compared to the example with a polystyrene core and a PMMA cladding as shown in the Figures. The NA could exceed about 0.9. The number of reflections in terms of the diameter core d length of fiber L critical angle α by: N=(cot α)L/d. The cladding must be >5 wavelengths thick.

Because the pores are far smaller than visible wavelengths, the resultant heterogeneous films can be considered uniform for the optical properties of visible light, and have an index of refraction for heterogeneous media given by several possible formulae2 which bracket the possible extremes: (a) Parallel: n˜fn_p+(1−f)n_o; (b) Series: 1/n˜f/n_p+(1−f)/n_o; or (c) Drude: n²˜fn²_p+(1−f)n²_o, where f is the porous fraction of the film, n_p is the pore index, equal to that of air (i.e. n_p=1) unless filled, and no is the oxide matrix index. The smallest measured index in the literature for porous anodic alumina (PAA) films is n=1.08³. For the form of PAA here (boehmite, γ-alumina), for example, no ˜1.75, and so for f=65% porosity, easily achieved, the index of the film is bracketed by n in the ranges of about 1.26/1.18/1.3, respectively, as calculated for the 3 formulae above, low enough to capture significantly more light in fibers with such a cladding. For n<1.33, such a material could pipe light from a water core n=1.33 (if the pores were sealed with an obliquely applied film, as commonly used in anodic products or with a steam oxidation). Low cladding n increases the trapping fraction significantly and enables far better detection of sensor signals or power delivery even with the thinnest fibers. At cladding n=1.3(1.08), with a core index of 1.6, the NA>0.9, approaching 1, and 9%(16%) of the light is transmitted, a factor of 3(5) over the best plastic fibers. For quartz cores (n=1.54), 8% of the light is transmitted. For a water-core cylindrical light guide, with a claddings of 1.26(1.08), 2.7% (9.4%) of light is transmitted per end.

Applications related to low index of refraction coatings include fiber-based analog sensors for chemistry, biomedical or industrial processes or others, where the light from a sensor at the end of the fiber must be captured by the fiber. The sensors either produce light proportional to a property or parameter being measured, or modify a light pulse proportionally to the property being measured. In either case, increasing the signal by about three to about 4 times is an important benefit to the signal to noise ratio or accuracy of the measurement.

A key application of these nanoporous claddings is that power delivery over fiber would be enhanced by these techniques. The dielectric breakdown of alumina as a cladding material would exceed typical high dielectric used in glass fibers by factors of about to about 10. Power over fiber could exceed about 2 to about 3 GWatt/mm2 (or ≧about 10 kW/10 μm core). Applications include: i) laser machining; ii) surgery; and iii) lighting. A 10 μm core fiber could deliver about 10 to about 15 horsepower electric, assuming 50% resonant conversion (i.e. the same wavelength photodiode as the laser driver; the laser could be the fiber itself). Drones-over-fiber could lift substantial objects for elevated construction or repair, such as tree work, painting, window cleaning, elevated wiring, or delivery of construction supplies.

The disclosed method can be used to make filters. Porous free standing edge anodic films can be used for filtration, but have the advantage of not needing to be back-thinned as used presently with anodic Al filters. As an example, a thin aluminum film backed by a stronger open web of structural material (for example, an aluminum film or sheet on top of a supporting mesh—the mesh with major diameter openings about 1 mm, between walls about 10% as wide as the mesh open diameter, in polymers, metals, ceramics or other structural materials) could then be edge anodized to form a filter of pores capable of removing particles down to virus sizes. The mesh is designed so that the pressure on the anodic film covering the mesh opening will not burst. If the mesh backing were metals or ceramics, the filter could be cleaned of organic/biologic materials by ashing at elevated temperatures. Because of the anisotropic pores, they can be cleaned by back-washing—a fibrous filter like paper HEPA filters—entraps particles and cannot be easily cleaned by flow reversal. With pore-widening, the porosity can be made exceptionally high, <70%, much exceeding the porosity of typical fibrous filters, <few %. Simple filter masks would be far easier to breath from, and self-clean with exhalation, capable of removing virus particles. In summary, these MIP EA filter can have the following properties: a) cleaning by refractory ashing; b) back-stream cleaning; c) highly uniform pore size distributions, with major diameters ranging from about a few μm to 10's of nm, in single sizes, or, with post-processing, multiple precise sizing; d) high porosity up to 70%; e) walls are functionizable to extract from or insert into the gas/liquid stream chemicals as the fluid passes through the filter.

There are also electronic and micro/nano electronic applications of the disclosed MIP EA where nanopores without underlying metal must contact with other electronics. These include: i) Z-Axis Connectors: where a dense array of nanopores, the pores perpendicular to a planar VLSI circuit, are created on a microcircuit. The nanopores are post-process filled with conducting metal nanowires. The resistance parallel to the surface (x,y) is insulative because of the oxide walls, whereas the resistance perpendicular (z-direction) is typical of metals; thusly 2 chips which present connection pads can be connected along the z-direction. If the pads on one chip are large enough, the placement can be without high precision placement—the z-axis connector serves as a fan-out of submicron pads on the underlying chip if areas on the topside are large enough for macroscopic connection. FIG. 23 shows a conventional z-axis connector. Instead, a nanoporous anodic alumina film would be fabricated on top of one chip, patterned with materials blocking areas of unwanted z-axis connections (such as polymers), the open pores made conductive with metal films or solid metal (via ALD, CVD, MBE or others), the blocked areas stripped off, followed by a brief chemical etch to dissolve a portion of the anodic film, leaving the metal posts slightly raised above the surface. A soft metal such as In or Pb is electroplated or functionalized ALD onto the exposed tips. The second chip would then be flipped and attached to the z-axis layer by compression and/or low temperature softening and melting. ii) Low Dielectric Constant Layers: near that of air, fully insulating, for high speed on-chip strip-lines or lowering the capacitive coupling of the lines on chips, or insulation of the gate layers of microfabricated transistors. iii) High Dielectric Layers: Anodic films filled with high dielectrics, for capacitors, where the anisotropy of the pores causes the dielectric constant to be larger in the pore direction, or to prevent dielectric breakdown by isolating the dielectric from neighboring pores. iv) Insulated Wires: Insulating copper, aluminum or other metallic wires, either microelectronic or macroscopic, by coating the wire with aluminum (or other) and then EA. The anodic coatings have high resistivity and operate at refractory temperatures. v) Lithographic masks: the pores on the sub-micron scale can be blocked or filtered or removed with the patterns used to process chips. For examples: a) to deliver light/x-rays, liquid, gas or plasma to specified areas of the chip; b) to block or resist areas to be protected from energy or chemistry. With appropriate etching of an anodic film on the chip, it can serve as a photolithographic contact mask. vi) Imaging Sensor Chips: a) An anodic porous film can be used as a pixel color filter by fabrication in-situ on top of an imaging chip by filling the resulting nano pores with the appropriate RGB or CYM or more colors filtering materials. Since the anodic film can be 10's of microns thick, very high color contrast can be had; b) the nanoporous anodic film can serve as a contact or “fly's-eye” collimator which may sharpen images and focus.

FIG. 23 is a perspective view of an example of a conventional Z-axis connector using indium bump bonds. Using the disclosed MIP EA method described, then instead of a conventional Z-axis connector using indium bump bonds, a nanoporous anodic alumina film would be fabricated on top of one chip, patterned with materials blocking areas of unwanted z-axis connections (such as polymers), the open pores made conductive with metal films or solid metal (via ALD, CVD, MBE or others), the blocked areas stripped off, followed by a brief chemical etch to dissolve a portion of the anodic film, leaving the metal posts slightly raised above the surface. A soft metal such as In or Pb is electroplated or functionalized ALD onto the exposed tips. The second chip would then be flipped and attached to the z-axis layer by compression and/or low temperature softening and melting.

The disclosed method can be used for the MIP of materials. For example, for a material with an inner process layer/volume where it is desired to have processing moving or expanding outwards to the workpiece surface. Thus MIP can be used as a modification of slice or layer processing which can be used mainly on soft, gel or liquid materials to be processed. Thus, MIP in this case comprises supplying the energy first into the interior of the workpiece with an array of fine delivery probes or energy focal points, arranged to be: i) consistent with the shape of the finished workpiece, and then controllably withdrawn so that the processing volume moves methodically to the surface of the workpiece; ii) the focal points or delivery probes are arranged as a planes or tiles of a closed surface inside the workpiece, which are then moved outward to the surface. For illustration, a “toy” example may be a spherical workpiece. A small spherical region in the center of the spherical workpiece would receive the first processing energy, and then an expanding spherical shell of processing would proceed, with the process energy growing with the square of the distance to the initial process start. In one embodiment of this is when UV, thermal, chemical, microwave, x-ray, electric current or other energy are needed to cure/process soft/viscous/liquid materials, but the cured the material decreases the transport of energy to underlying unprocessed material. As a specific example, some materials become opaque to the UV when cured by UV. If UV flood-illuminated from the surface, a workpiece has a cured surface layer which stops or inhibits the curing of the bulk. Instead, a soft or liquid material could be cured beyond the surface layer by, for example, immersing the energy curing source into a workpiece with a volume shape fitted to the shape of the workpiece, and then moving and expanding area of the energy source towards the surface of the workpiece, curing the entire workpiece, rather than just the surface. A UV-cure example might be an array of UV emitting lasers or LED, focused with variable focal lenses towards the center of the workpiece, such that the energy in the unfocussed parts of the beam are less than sufficient for curing. The foci are then decreased and rastering away from the center. X-ray, gamma-ray or particle beam cured workpieces could utilize energy focused similarly. A similar example is an array of UV transmitting optical fibers or capillaries with a chemical hardener inserted into a polymer precursor at various depths to be cured and then withdrawn. For example, a thermally driven process, where a workpiece is normally immersed into a heat source or bath, and the process makes the material thermally insulative, heat energy is injected via conduction probes or focused microwave or IR energy, and controllably exposed outwards from the interior towards the surface.

The disclosed method can be used for the MIP of materials in a rastered small process volume case such as manufacturing a 3d part tool. This embodiment of MIP has similarities to 3D additive printing tools. Instead of adding material with a stepped raster to form a part, in the MIP case, a very small volume of processing energy is rastered through the volume of a precursor material, so that the processed material, slice by slice forms the workpiece. This can be applicable to liquid or very soft volumes of precursor, where a part would be produced from processing the liquid or slurry into a solid (as in plastic cross-linking or ceramic greenforms or metal sintering preforms), or other material volumes were the unprocessed material precursor could be easily removed (examples: dissolved, thermally chemically removed, or any other processes which do not affect the MIP-processed part). One example would be a volume of liquid precursor—a UV curable liquid plastic or a sintering slurry. A “processing head” of processing energy (often similar to a 3D “print-head” but not for additive deposition; rather for processing energy or technique) device would be rastered through the volume of the liquid, turned on and off where the part needed to be formed by curing/processing rather than by deposition as in present 3D printers.

For example, a UV optical fiber with a microlense or diffusor at the far end, and driven with deep UV light that had a sub-mm absorption length in the liquid could form the “pixels” and then slices of a part.

Another embodiment would use a pulsed thermal tip to process ceramic green form slurries into a part. The remaining unprocessed liquid or slurry would be drained off to be used again.

Another realization of this would be to deposit a thin layer (a thin film) of precursor material on the bottom of the inside of a processing tank, and the processing head would then solidify the slice of a 3D part. Another thin layer or film of liquid or soft material would be deposited and the process head would repeat for the second slice. The processing head could be a scanning laser, like a laser printer; a capillary or ink-jet like chemical dispenser; a thermal pulse head; electrode(s); or others.

The general technique described herein is controlled movement of a processing energy or process technique, which is otherwise normally applied to the entire outer surface of a workpiece, but does not readily process the entire volume of the workpiece, and inhibits further processing below the surface exposed to the process. A specified small area, slice or volume is processed and the process energy is then moved methodically through the entire volume of the workpiece. The process energy may be electric current as in anodization, focused or delivered UV, visible, IR or microwave electromagnetic energy, chemical energy, thermally conducted energy or other techniques where the processing normally does not penetrate to sufficient depth. The workpiece is moved relative to a fixed process surface or volume, or the processing technique surface or volume is moved relative to the fixed workpiece. Prime examples include: a) complete or much thicker anodization of metal parts, where an edge of a metal workpiece is methodically immersed at controlled rates into an anodizing bath; b) liquid or soft precursor materials (plastics, gels, sintering slurries, greenforms, and the like) processed into solid shapes via injection of light over the volume. Examples include electromagnetic energy focusing, optical fibers, electrical or thermal contacts, or capillary injection of chemical hardeners or reactants and similar array processing; c) a form of 3D part manufacturing based on processing a 3D part out of a volume or successive thin films of precursor by rastering a hardening process throughout the volume of a precursor via a “process head”, rather than by additive 3D printing head.

The disclosed invention has many advantages. The MIP technique may be of general use when layers of processed material inhibit processing of materials below the processed layer. The processing may be almost any form of energy or chemical/material energy which would be applied to the surface of a work-piece but would be very advantageous to be extended to much thicker surface layers or to the workpiece entirely. The disclosed MIP method has many applications to existing materials surface processing that are low cost, with tunable properties, and easily industrially scalable process for both new products and for added value to many existing products which could utilize, for example, hardness, porosity, optical transparency, low index of refraction, functionizable, or combinations of the aforementioned properties of materials processed using MIP. In general, MIP may be applicable to materials where a materials-process applied to a bulk piece of the material would normally terminate in a surface film or layer leaving the bulk material unprocessed. The MIP process enables complete processing of the bulk material or much thicker films of the processed material on unprocessed bulk material. Other advantages include: la. Hard Coating: used as a hard coating process for transparent materials, it preserves the transparency of the underlying material, and if also fabricated as porous with pore diameters less than optical wavelengths can be tuned in index of refraction to match that of the underlying transparent material, or to also serve as an antireflective, reflective or wavelength-selective (dichroic or absorptive filtering) coating in reflection or transmission. lb. Hard Coating: Generally the process is low cost and can be applied to a wide variety of solid materials—metals, glass, plastics and polymers, ceramics, oxides for examples—i.e. wherever anodizable thin metal films (Al, Mg, Zn, and Ti, primarily) can be deposited either uniformly or as a dense array of patches with electrical connections to the nearest neighbor patches. 2a. Optics: Low index of refraction materials and tunable index of refraction materials due to high and tunable percentages of porosity. 2b: Optics Optical Devices: Optical fibers with high numerical apertures approaching 0.9 by ultra-low index cladding using pores at least 10× smaller than the wavelengths of light and 70% open area, which could transport up to 400% more light than standard commercial fibers. 2c: Optics: Optical Devices: Optical wavelength filter arrays for precision imaging with highly selective colors—the highly anisotropic pores on sub-micron diameters when appropriately patterned with dyes can be used to create 3- or far-more color arrays for filtering image chips with greater fidelity since the dyes are confined to columns which are much thicker than can be applied as a normal filter film to a sensor pixel. Similarly, image reproduction can have high precision when white light is filtered through these dense arrays of pores, either in imaging displays or as printer “paper”. 3a. Functionizable coatings due to the high porosity; the pores can be filled with materials that deliver materials or accept materials with specific properties, such as hydro-philic or -phobic, dyes, conductive materials, medicine delivery, precision chemical or medical sampling/aliquots, and other materials to be sampled or delivered, either on specific surfaces or as free-standing porous films or foils. 4a. Manufacturable: Can be applied in roll-to-roll or similar continuous processes on foils (sheets) or filaments (wires), and can be used sequentially in different processing stations to add functional materials or to enhance porosity or to seal pores or other sequential processing steps. 4b: Manufacturable: Can be scaled to process large parts in parallel. 4c: Manufacturable: Amenable to quality control using feedback from sensors to control the process via temperature, speed, energy density, voltage, current, resistance, pH, chemistry makeup, ionization, applied spatial sizes and shapes, optical, thermal and process energy absorption, and their temporal gradients. 5a: Electronics: Very low K and high frequency dielectric films via porous oxides—for insulating transmission lines/interconnects on microcircuits, and 5b: Electronics conversely in porous materials dense arrays of high dielectrics via the spatial anisotropy in the pores but insulated from each other to minimize breakdown and maximize voltage and energy density in capacitors and capacitive electrical energy storage. 5c: Electronics: Free standing films or sheets of highly anisotropic magnetic films for sensors based on moving magnets, or for magnetic-based memory. 5d: Electronics: vias or highly anisotropic conducting films with low resistance perpendicular to the sheet and high resistance in the 2 orthogonal directions lying in the surface of the sheet for connecting circuits in the direction perpendicular to the circuit. 6a: Filters: free-standing filters with up to 70% open area using the standard edge anodization MIP process on Al, or even larger with post-processing pore widening steps, or precision (±2 nm), uniform (±1% or less) pore diameters as fine a few nm via pore coating, that can be cleaned via high temperature ashing and reverse flow. 6b: Filters: that can be made biocompatible, and 6c: Filters that can be coated with materials to deliver to flow stream, such as medicines or other dissolvable materials needed in low concentrations. 6d: Filters: filters with sufficient percentage of open area/free flow that they could be used long term in human masks without the need for mechanical blower assist, and compact enough to be used as nostril and mouth inserts.

It should be noted that the terms “first”, “second”, and “third”, and the like may be used herein to modify elements performing similar and/or analogous functions. These modifiers do not imply a spatial, sequential, or hierarchical order to the modified elements unless specifically stated.

While the disclosure has been described with reference to several embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the disclosure. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the disclosure without departing from the essential scope thereof. Therefore, it is intended that the disclosure not be limited to the particular embodiments disclosed as the best mode contemplated for carrying out this disclosure, but that the disclosure will include all embodiments falling within the scope of the appended claims.

Claims

1. A method of moving interface processing of materials, the method comprising:

providing a working material;

providing an energy source adjacent to the working material;

providing for relative controlled movement between the working material and the energy source;

activating the energy source such that the energy processes the working material;

moving the energy source and/or the working material relative to the other to control the amount of processing of the working material achieved by the energy.

2. The method of claim 1, wherein:

the working material is a piece of aluminum;

the energy source is electrical current between a cathode and the working material as an anode;

the relative controlled movement is a motor attached to the working material via a linkage; and

the processing of the working material is anodization.

3. The method of claim 1, wherein:

the energy source is selected from the group consisting of ultra violet light, infrared light, visible light, microwaves, chemical energy, and thermal energy.

4. An apparatus for the moving interface processing of materials, the apparatus comprising:

working material;

an energy source adjacent to the working material;

a means for providing for relative controlled movement between the working material and the energy source such that the amount of processing of the working material achieved by the energy from the energy source is controlled.

5. The method of claim 2, further comprising:

methodically and smoothly immersing the working material at a controlled speed into anodizing bath equipped with a cathode;

starting anodization of the working material at the edge of the working material furthest from the anode connection and just below the anodization bath,

immersing the working material into the bath such that the anodization is moved up the working material towards the edge nearest the anode connection, resulting in generally complete conversion to oxide, except for a vanishingly small or insignificant metal or conductive edge where the anode voltage is connected to the workpiece.

6. The method of claim 5, further comprising:

removing the generally non-anodized portion from the working material.

7. The method of claim 5, wherein the working material is an aluminum foil deposited on a non-conducting substrate.

8. The method of claim 7, further comprising:

anodizing the aluminum foil into a transparent aluminum-oxide layer.

9. The method of claim 1, wherein:

the working material is an Al film at about 99.99% purity;

the power supply is a bi-polar power supply capable of at least about ±150V;

the process is an edge anodization process;

the relative controlled movement between the working material and the energy source is a motor capable of providing sub-micron linear motion, over a distance a least as long as the working material with a programmable controller capable of about under millisecond steps, installed appropriately on the anodizing bath vessel;

wherein the method further comprises:

providing an anodizing bath vessel of an inert plastic, with a Pb cathode;

providing an anodizing bath;

providing thermal measurement controls of the anodizing bath;

providing agitation and mixing of the anodizing bath;

providing a chemical cleaning/rinsing baths, etching/rinsing baths, and de-Ox/rinse baths of working material to present bare metal to the Edge Anodization process.

mounting the working material to a connector in operable communication with the motor;

connecting the power supply the working material and the Edge Anode, and cathode.

providing a post-rinse bath; and

providing post processing such as pore sealing, and pore filling to the processed working material.

10. A transparent coating manufactured by the process of claim 1.

11. A scratch resistant coating manufactured by the process of claim 1.

12. Films of porous anodized materials manufactured by the process of claim 1.

13. Low index of refraction coatings manufactured by the process of claim 1.

14. Porous free standing edge anodic films used for filters manufactured by the process of claim 1.

15. The method of claim 1, wherein:

the working material is a soft solid, gel or liquid;

the providing for relative controlled movement between the working material and the energy source act, further comprises: supplying energy to the interior of the working material with an array of fine delivery probes or energy focal points, arranged to be: i) consistent with the shape of the finished workpiece; controllably withdrawing the energy so that a processing volume moves methodically to the surface of the working material; and arranging the delivery probes or focal points as planes or tiles of a closed surface inside the workpiece, which deliver probes or focal points are then moved outward to the surface.

16. The method of claim 1, wherein the energy is UV light.

17. The method of claim 1, wherein:

the working material is a soft solid, gel or liquid;

the providing for relative controlled movement between the working material and the energy source act, further comprises: rastering a very small volume of processing energy through a volume of the working material in a slice by slice manner.

18. An apparatus for the moving interface processing of materials, the apparatus comprising:

an anodizing bath;

a cathode located in the anodizing bath;

a power supply in communication with the cathode, and the power supply configured to be in communication with a working material at an anode connection such that a portion of the working material acts as an anode;

a motor configured to accurately and methodically move the a working material into the anodizing bath such that anodization of the working material begins at the edge of the working material furthest from the anode connection and just below the anodization bath, and the motor is further configured to immerse the working material into the bath such that the anodization is moved up the working material towards the edge nearest the anode connection, resulting in generally complete conversion to oxide, except for a vanishingly small or insignificant metal or conductive edge adjacent or at the anode connection.