ELECTRONICALLY ADDRESSABLE MICROENCAPSULATED INK AND DISPLAY THEREOF
A system of electronically active inks is described which may include electronically addressable contrast media, conductors, insulators, resistors, semiconductive materials, magnetic materials, spin materials, piezoelectric materials, optoelectronic, thermoelectric or radio frequency materials. We further describe a printing system capable of laying down said materials in a definite pattern. Such a system may be used for instance to: print a flat panel display complete with onboard drive logic; print a working logic circuit onto any of a large class of substrates; print an electrostatic or piezoelectric motor with onboard logic and feedback or print a working radio transmitter or receiver.
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This application is a divisional of copending application Ser. No. 10/652,218, filed Aug. 29, 2003, which is a continuation of U.S. Ser. No. 10/200,571, filed Jul. 22, 2002 (now U.S. Pat. No. 6,652,075), which is a continuation of U.S. Ser. No. 09/471,604, filed Dec. 23, 1999 (now U.S. Pat. No. 6,422,687), which is a divisional of U.S. Ser. No. 08/935,800, filed Sep. 23, 1997 (now U.S. Pat. No. 6,120,588), which claims priority to U.S. Provisional Application No. 60/035,622, filed Sep. 24, 1996, and claims priority to and is a continuation-in-part of International Application PCT/US96/13469, filed Aug. 20, 1996, which claims priority to U.S. Provisional Application No. 60/022,222, filed Jul. 19, 1996, the entire disclosures of which applications are incorporated herein by reference in their entirety.BACKGROUND OF INVENTION
Currently, printing of conductors and resistors is well known in the art of circuit board manufacture. In order to incorporate logic elements the standard practice is to surface mount semiconductor chips onto said circuit board. To date there does not exist a system for directly printing said logic elements onto an arbitrary substrate.
In the area of flat panel display drivers there exists technology for laying down logic elements onto glass by means of vacuum depositing silicon or other semiconductive material and subsequently etching circuits and logic elements. Such a technology is not amenable to laying down logic elements onto an arbitrary surface due to the presence of the vacuum requirement and the etch step.
In the area of electronically addressable contrast media (as may be used to effect a flat panel display) emissive and reflective electronically active films (such as electroluminescent and electrochromic films), polymer dispersed liquid crystal films, and bichromal microsphere elastomeric slabs are known. No such directly electronically addressable contrast medium however is amenable to printing onto an arbitrary surface.
Finally in the area of surface actuators electrostatic motors, which may be etched or non-etched, are known in the art. In the first case, such etched devices suffer from their inability to be fabricated on arbitrary surfaces. In the second case, non-etched devices suffer from the inability to incorporate drive logic and electronic control directly onto the actuating surface.
It is an object of the present disclosure to overcome the limitations of the prior art in the area of printable logic, display and actuation.SUMMARY OF THE INVENTION
In general the present invention provides a system of electronically active inks and means for printing said inks in an arbitrary pattern onto a large class of substrates without the requirements of standard vacuum processing or etching. Said inks may incorporate mechanical, electrical or other properties and may provide but are not limited to the following function: conducting, insulating, resistive, magnetic, semiconductive, light modulating, piezoelectric, spin, optoelectronic, thermoelectric or radio frequency.
In one embodiment this invention provides for a microencapsulated electric field actuated contrast ink system suitable for addressing by means of top and bottom electrodes or solely bottom electrodes and which operates by means of a bichromal dipolar microsphere, electrophoretic, dye system, liquid crystal, electroluminescent dye system or dielectrophoretic effect. Such an ink system may be useful in fabricating an electronically addressable display on any of a large class of substrate materials which may be thin, flexible and may result in an inexpensive display.
In another embodiment this invention provides for a semiconductive ink system in which a semiconductor material is deployed in a binder such that when said binder is cured a percolated structure with semiconductive properties results.
In another embodiment this invention for provides for systems capable of printing an arbitrary pattern of metal or semiconductive materials by means of photoreduction of a salt, electron beam reduction of a salt, jet electroplating, dual jet electroless plating or inert gas or local vacuum thermal, sputtering or electron beam deposition.
In another embodiment this invention provides for semiconductor logic elements and electro-optical elements which may include diode, transistor, light emitting, light sensing or solar cell elements which are fabricated by means of a printing process or which employ an electronically active ink system as described in the aforementioned embodiments. Additionally said elements may be multilayered and may form multilayer logic including vias and three dimensional interconnects.
In another embodiment this invention provides for analog circuits elements which may include resistors, capacitors, inductors or elements which may be used in radio applications or magnetic or electric field transmission of power or data.
In another embodiment this invention provides for an electronically addressable display in which some or all of address lines, electronically addressable contrast media, logic or power are fabricated by means of a printing process or which employ an electronically active ink system as described in the aforementioned embodiments. Such display may further comprise a radio receiver or transceiver and power means thus forming a display sheet capable of receiving wireless data and displaying the same.
In another embodiment this invention provides for an electrostatic actuator or motor which may be in the form of a clock or watch in which some or all of address lines, logic or power are fabricated by means of a printing process or which employ an electronically active ink system as described in the aforementioned embodiments.
In another embodiment this invention provides for a wrist watch band which includes an electronically addressable display in which some or all of address lines, electronically addressable contrast media, logic or power are fabricated by means of a printing process or which employ an electronically active ink system as described in the aforementioned embodiments. Said watch band may be formed such that it has no external connections but rather receives data and or power by means of electric or magnetic field flux coupling by means of an antennae which may be a printed antennae.
In another embodiment this invention provides for a spin computer in which some or all of address lines, electronically addressable spin media, logic or power are fabricated by means of a printing process or which employ an electronically active ink system as described in the aforementioned embodiments.
Further features and aspects will become apparent from the following description and from the claims.BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing and other objects, features and advantages of the invention will be apparent from the following more particular description of preferred embodiments of the invention, as illustrated in the accompanying drawings in which like reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention.
FIGS. 1A-F are schematic representations of means of fabricating particles with a permanent dipole moment.
FIGS. 2A-C are schematic representations of means of microencapsulation.
FIGS. 3A-E are schematic representations of microencapsulated electronically addressable contrast media systems suitable for top to bottom addressing.
FIGS. 4A-M are schematic representations of microencapsulated electronically addressable contrast media systems suitable for bottom addressing.
FIGS. 5A-D are schematic representations of microencapsulated electronically addressable contrast media systems based on a dielectrophoretic effect.
FIGS. 6A-B are schematic representations of microencapsulated electronically addressable contrast media systems based on a frequency dependent dielectrophoretic effect.
FIGS. 6C-E are plots of the dielectric parameter as a function of frequency for various physical systems.
FIGS. 7A-D are schematic representations of electronic ink systems and means for printing the same.
FIGS. 9A-E are schematic representations of electronic ink systems and means for printing the same.
FIGS. 10A-C are schematic diagrams of printed transistor structures.
FIGS. 10E-H are schematic diagrams of printed analog circuit elements.
FIGS. 11A-C are a schematic diagram of an electronic display employing printed elements which; this display may further include a data receiver or transceiver and a power means.
FIGS. 13A-B are a schematic diagram of a watch in which the wristband of said watch incorporates an electronically addressable display having printed elements and which may further comprise wireless means for sending or receiving data or power between watch and watchband.
Means are known in the prior art for producing bichromal particles or microspheres for use in electronic displays. Such techniques produce a particle that does not have an implanted dipole moment but rather relies in general on the Zeta potential of the material to create a permanent dipole. Such a scheme suffers from the fact that it links the material properties to the electronic properties thus limiting the size of the dipole moment which may be created.
A large number of techniques are known in the literature for microencapsulating one material inside of another material. Such techniques are generally used in the paper or pharmaceutical industry and do not generally produce a microcapsule which embodies simultaneously the properties of optical clarity, high dielectric strength, impermeability and resistance to pressure. With proper modification however these techniques may be made amenable to microencapsulating systems with electronic properties.
An alternate means of microencapsulation is shown in
Employing the systems described in FIGS. 2A-C it is possible to microencapsulate systems with electronically active properties specifically electronically addressable contrast media.
Referring to FIGS. 3C-D, a microcapsule 120 may contain a dye, dye precursor or dye indicator material of a given charge polarity 230 or a dye, dye precursor or dye indicator material attached to a particle of given charge polarity such as a microsphere with an appropriate surface group attached and a reducing, oxidizing, proton donating, proton absorbing or solvent agent of the other charge polarity 240 or a reducing, oxidizing, proton donating, proton absorbing or solvent agent attached to a particle of the other charge polarity. Under application of an electric field said dye substance 230 is maintained distal to said reducing, oxidizing, proton donating, proton absorbing or solvent agent 240 thus effecting one color state as in
Referring to FIGS. 4A-M, it may be desirable to develop ink systems which are suitable for use without a top transparent electrode 100 which may degrade the optical characteristics of the device. Referring to
As another system in-plane switching techniques have been employed in transmissive LCD displays for another purpose, namely to increase viewing angle of such displays. Referring to
Other systems may be created which cause a first color change by means of applying an AC field and a second color change by means of application of either a DC field or an AC field of another frequency. Referring to FIGS. 4F-G, a hairpin shaped molecule or spring in the closed state 284 may have attached to it a positively charged 282 and a negatively charged 283 head which may be microspheres with implanted dipoles. Additionally one side of said hairpin shaped molecule or spring has attached to it a leuco dye 286 and the other side of said hairpin shaped molecule or spring has attached to it a reducing agent 285. When said molecule or spring is in the closed state 284 then said leuco dye 286 and said reducing agent 285 are brought into proximity such that a bond is formed 287 and said leuco dye is effectively reduced thus effecting a first color state. Upon a applying an AC electric field with frequency that is resonant with the vibrational mode of said charged heads cantilevered on said hairpin shaped molecule or spring said bond 287 may be made to break, thus yielding an open state 288. In said open state the leuco dye and reducing agent are no longer proximal and the leuco dye, being in a non-reduced state, effects a second color state. The system may be reversed by applying a DC electric field which serves to reproximate the leuco dye and reducing agent groups. Many molecules or microfabricated structures may serve as the normally open hairpin shaped molecule or spring. These may include oleic acid like molecules 289. Reducing agents may include sodium dithionite. The system as discussed is bistable. Energy may be stored in said hairpin shaped molecule or spring and as such said system may also function as a battery.
Referring to FIGS. 4I-K an alternative leucodye-reducing agent system may employ a polymer shown in
Referring to FIGS. 5A-D and FIGS. 6A-B an entirely different principle may be employed in an electronically addressable contrast media ink. In these systems the dielectrophoretic effect is employed in which a species of higher dielectric constant may be caused to move to a region of high electric field strength.
Referring to FIGS. 6A-B, systems based on a frequency dependent dielectrophoretic effect are described. Such systems are addressed by means of applying a field of one frequency to produce a given color and applying a field of a different frequency to produce another color. Such a functionality allows for a rear addressed display.
Alternatively material 182 may be comprised of naturally occurring frequency dependent dielectric materials. Materials which obey a frequency dependence functionality similar to the artificially created dipole material discussed above and which follow curves similar to
Additionally material 182 may be a natural or artificial cell material which has a dielectric constant frequency dependence as depicted in
It is understood that many other combinations of particles with frequency dependent dielectric constants arising from the physical processes discussed above may be employed to effect a frequency dependent electronically addressable display.
In addition to the microencapsulated electronically addressable contrast media ink discussed in
In one system a semiconductor ink 350 may be fabricated by dispersing a semiconductor powder 355 in a suitable binder 356. Said semiconductor powder may be Si, Germanium or GaAs or other suitable semiconductor and may further be with n-type impurities such as phosphorus, antimony or arsenic or p-type impurities such as boron, gallium, indium or aluminum or other suitable n or p type dopants as is known in the art of semiconductor fabrication. Said binder 356 may be a vinyl, plastic heat curable or UV curable material or other suitable binder as is known in the art of conducting inks. Said semiconductive ink 350 may be applied by printing techniques to form switch or logic structures. Said printing techniques may include a fluid delivery system 370 in which one or more inks 372, 374 may be printed in a desired pattern on to a substrate. Alternatively said ink system 350 may be printed by means of a screen process 377 in which an ink 380 is forced through a patterned aperture mask 378 onto a substrate 379 to form a desired pattern. Said ink pattern 360 when cured brings into proximity said semiconductive powder particles 355 to create a continuous percolated structure with semiconductive properties 365.
Alternatively a field effect transistor may be printed such as a metal oxide semiconductor. Such a transistor consists of a p-type material 970, an n-type material 966 an n-type inversion layer 968 an oxide layer 962 which acts as the gate a source lead 960 and a drain lead 964. It is readily understood that multiple layers of logic may be printed by using an appropriate insulating layer between said logic layers. Further three dimensional interconnects between different logic layers may be accomplished by means of vias in said insulating layers.
Referring to FIGS. 10E-H elements useful for analog circuitry may be printed. Referring to
Referring to FIGS. 10F-H inductors, chokes or radio antennae may be printed layer by layer. Referring to
The ink systems and printing means discussed in the foregoing descriptions may be useful for the fabrication of a large class of electronically functional structures.
Said power block 674 may comprise a printed polymer battery as pictured in
Such a display 600 as described above further comprising a data receiver or transceiver 672 and power block 674 in which some or all of said components are printed may comprise an inexpensive, lightweight, flexible receiver for visual data and text which we may term “radio paper.” In such a system data might be transmitted to the “radio paper” sheet and there displayed thus forming a completely novel type of newspaper, namely one which is continuously updated.
While this invention has been particularly shown and described with references to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.
1. A movable head for printing an electrically active material, the head comprising:
- (a) an inert gas chamber; and
- (b) a thermal, sputtering, or electron beam for depositing the material.
2. An inkjet apparatus comprising a movable head according to claim 1 in combination with means for changing the temperature of a substrate.
3. An inkjet apparatus according to claim 2 further comprising means for generating a beam of ultraviolet radiation.
4. An electro-optic display component comprising a molecule having:
- (a) a first portion with a first charge; and
- (b) a second portion with a second charge whereby the application of an electric field, or a frequency change in such a field, changes the perceived optical state of said molecule.
5. An electronic display component according to claim 4 manufactured by a process comprising:
- (a) providing a radiation-curable substrate;
- (b) imagewise exposing said radiation-curable substrate to a radiation source, thereby forming a plurality of individual cells in said radiation-curable substrate; and
- (c) filling at least one of said plurality of individual cells with a contrast medium comprising a suspending fluid and said molecule, thereby said filled cell forms said electronic display component.
6. An electronic display component according to claim 4 in combination with electric field generation means arranged to apply at least one of a DC field and an AC field to said component.
7. An electro-optic display component comprising a microcavity filled with a suspending fluid and a microfabricated structure, said structure having:
- (a) a first part with a first charge; and
- (b) a second part with a second charge whereby the application of an electric field, or a frequency change in such a field, changes the perceived optical state of said structure.
8. An image display operating by electrophoretic or dielectrophoretic principle wherein a charged particle species is replaced by a microfabricated structure having a first part with a first charge and a second part with a second charge.
9. An electronic display component according to claim 8 in combination with electric field generation means arranged to apply at least one of a DC field and an AC field to said display.
10. A printable semiconductor ink comprising a semiconductor powder dispersed in a binder.
11. A printable semiconductor ink according to claim 10 wherein the semiconductive powder comprises any one or more of silicon, germanium, gallium arsenide, phosphorus, antimony, arsenic, boron, gallium, indium, aluminum, a p-type dopant and an n-type dopant.
12. A printable semiconductor ink according to claim 10 wherein the binder comprises a vinyl, heat-sensitive or ultra-violet sensitive polymer.
13. A substrate coated with a semiconductor ink according to claim 10.
14. A logic structure for a flat panel display comprising a semiconductor ink according to claim 10.
15. A flat panel display comprising a logic structure according to claim 14.
16. An electronic device comprising the flat panel display of claim 15.
17. A printer cartridge or printer supply comprising a semiconductor ink according to claim 12.
18. A battery, solar cell, antenna, or computer produced by a method according to claim 12.
International Classification: B41J 2/05 (20060101);