THERMALLY CONTROLLED FLUIDIC SELF-ASSEMBLY
Methods and apparatuses are provided for assembling a structure on a support having a pattern of binding sites. In accordance with the method, a first fluid is provided on the surface of the support with the first fluid being of a type that that increases viscosity when cooled, the first fluid having first micro-components suspended therein each adapted to engage the binding sites. First fluid proximate to selected binding sites is cooled to increase the viscosity of the responsive fluid proximate to the selected binding sites so that the first micro-components suspended in the first fluid are inhibited from engaging the selected binding sites.
This Application is a Divisional of previously filed U.S. patent application Ser. No. 11/021,120, entitled: THERMALLY CONTROLLED FLUIDIC SELF-ASSEMBLY, filed on Dec. 22, 2004, in the names of Ravi Sharma et al., which is hereby incorporated herein by reference in its entirety.
Reference is made to commonly assigned, U.S. patent application Ser. No. 10/849,302, entitled: THERMALLY CONTROLLED FLUIDIC SELF-ASSEMBLY METHOD AND SUPPORT, filed on Sep. 3, 2004, in the names of Daniel D. Haas et al. (which was abandoned on Aug. 5, 2009); and U.S. patent application Ser. No. 10/849,329, entitled: THERMALLY CONTROLLED FLUIDIC SELF-ASSEMBLY AND CONDUCTIVE SUPPORT, filed on Sep. 3, 2004, in the names of Theodore K. Ricks et al. (which has since issued as U.S. Pat. No. 7,251,882, issued on Aug. 7, 2007).
FIELD OF THE INVENTIONThe present invention relates to methods for fluidic micro-assembled structure and, in particular, to methods and apparatuses for selective fluidic assembly of micro-components.
BACKGROUND OF THE INVENTIONMicro-assembled devices offer the promise of an entirely new generation of consumer, professional, medical, military, and other products having features, capabilities and cost structures that cannot be provided by products that are formed using conventional macro-assembly and macro-fabrication methods. For example, there is a need, particularly in the field of flat panel displays, smart cards and elsewhere, for microelectronic devices or chips that can be integrated into or assembled as either a system or as an array, in a relatively inexpensive manner. In another example, there is a need for a cost effective method for allowing accurate and cost effective assembly of colored display elements such as electrophoretic beads in specific locations on display panels.
One advantage of such micro-assembled devices is that they can utilize different materials and devices (a process generally termed heterogeneous integration) in ways that create new product possibilities. For example, such heterogeneous integration provides the opportunity for relatively rigid structures such as such as silicon transistors or other electronic devices to be assembled into more complex electronic circuits using a flexible substrate as opposed to the rigid silicon substrates currently used for this purpose. In this example, such heterogeneous integration would provide a less expensive means to assemble silicon based integrated circuit components and/or any other kind of circuit components to form integrated circuits on flexible or rigid supports that are not made from silicon. However, it will be appreciated that in providing such heterogeneous integrated circuits, it is necessary that these processes provide for precise placement of multiple types of independent structures on the substrate. Such heterogeneous integration can also be used for other purposes. For example, heterogeneous integration can be used for purposes such as the assembly of pharmaceutical products, advanced materials, optical structures, switching structures, and biological structures.
Of particular interest in the electronic industry is the potential for micro-assembly to solve existing problems in the assembly of highly desirable but complex structures used in forming electronic displays. Typical electronic displays use a structure known as a “front plane” as the image forming surface. The “front plane” comprises an arrangement of image forming elements also known as active elements formed from structures such as liquid crystals, electroluminescent materials, organic light emitting diodes (OLEDs), up converting phosphors, down converting phosphors, light emitting diodes, electrophoretic beads, or other materials that can be used to form images. Such active elements typically form images when an electric field or some other stimulus or other field is applied thereto. Such electronic displays also incorporate a structure known as a “back plane” that comprises structures such as electrodes, capacitors, transistors, conductors, and pixel drivers and other circuits and integrating components that are intended to provide appropriate stimulus to the active components to cause the active components to present an image. For example, the active components can react to stimulus by emitting controlled amounts of light or by changing their reflectivity or transmissivity to form an image on the front plane.
It is well known to use heterogeneous integration methods to place elements on a substrate. Such heterogeneous integration methods can be generally divided into one of two types: deterministic methods and random methods. Deterministic methods use a human or robotic structure to place individual elements into particular locations on the substrate. Such methods are also known as “pick and place” methods. Such “pick and place” methods offer two advantages: complete control and positive indication that components have been appropriately placed in a desired location. Further, such “pick and place” methods also allow the precise assembly of different types of micro-components to form a micro-assembled structure that integrates different types of materials, micro-assembled structures and components.
It will be appreciated that deterministic methods require a high degree of precision by the person or machine executing the deterministic assembly process. Accordingly, such deterministic methods are difficult to apply in a cost effective manner. This is particularly true where the assembly of micro-components is to occur at a high rate of assembly or where large-scale assembly of micro-components is to be performed such as is required in commercial, pharmaceutical, or other applications.
Random placement methods such as fluidic self-assembly have been used to integrate electronic devices such as GaAs LEDs onto silicon substrates. Fluidic self-assembly is a fabrication process whereby a large number of individual shaped micro-assembled structures are integrated into correspondingly shaped recesses on a substrate using a liquid medium for transport. This method of self-assembly relies on gravitational and shear forces to drive the self-assembly of micro-components. Examples of this include U.S. Pat. No. 5,545,291, entitled: METHOD FOR FABRICATING SELF-ASSEMBLING MICRO-ASSEMBLED STRUCTURES”, filed on Dec. 17, 1993, in the names of Smith et al.; U.S. Pat. No. 5,783,856, entitled: METHOD FOR FABRICATING SELF-ASSEMBLING MICRO-ASSEMBLED STRUCTURES, filed on May 9, 1995, in the names of Smith et al.; U.S. Pat. No. 5,824,186, entitled: METHOD AND APPARATUS FOR FABRICATING SELF-ASSEMBLING MICRO-ASSEMBLED STRUCTURES, filed on Jun. 7, 1995, in the names of Smith et al.; and U.S. Pat. No. 5,904,545, entitled: APPARATUS FOR FABRICATING SELF-ASSEMBLING MICRO-ASSEMBLED STRUCTURES, filed on Jun. 7, 1995, in the names of Smith et al.
Other approaches have been developed for using fluidic self-assembly to build a micro-assembled structure without relying exclusively on gravitational and/or shear forces. Some of these are illustrated in
In
In the prior art illustrated in
Electrostatic attraction has been proposed for use in positioning micro-components during micro-assembly. U.S. Patent Application Publication No. 2002/0005294, entitled: DIELECTROPHORESIS AND ELECTRO-HYDRODYNAMICS MEDIATED FLUIDIC ASSEMBLY OF SILOCON RESISTORS, in the names of Mayer, et al.; and S. W. Lee et al. (S. W. Lee et al., “Electric-Field-Mediated Assembly of Silicon Islands Coated with Charged Molecules”, Langmuir 2002, Vol. 18, pp. 3383-3386, January 2002), describe such methods.
As noted above, many micro-assembled structures incorporate a variety of different types of micro-components. Thus, heterogeneous integration of more than one type of micro-component using such a massively parallel random placement process, such as fluidic micro-assembly, is highly desirable. What is needed therefore is a method for assembling micro-components into a micro-assembled structure on the massive scale enabled by random placement methods such as conventional fluidic assembly but with the precision and selective assembly capabilities of deterministic methods.
Modifications to at least one of the fluidic self-assembly methods described above have been proposed in an attempt to meet this need. For example, in one approach, conventional fluidic assembly techniques have evolved that use differently shaped micro-components that are adapted to engage differently shaped receptor sites on a substrate. This requires that the substrate has binding sites that are uniquely shaped to correspond to a shape of a particular type of micro-component. However, the constraints of surface etching techniques, micro-component formation techniques, cost, electrical function, and orientation limit the number of shape configurations that are available for use in discrimination, which in turn limits the number of different components that can be placed on the substrate using such a process.
In another approach, Bashir et al. discusses the use of binding between complementary DNA molecules or ligands to discriminate between binding sites. While this approach provides a high degree of differentiation high cost may be encountered in patterning the DNA or ligands on the substrate. (H. McNally et al., “Self-assembly of micro- and nano-scale particles using bio-inspired events”, Applied Surface Science, Vol. 214/1-4, pp. 109-119, 2003).
Thus, there is a need for a more cost effective method for the high volume heterogeneous assembly of micro-components.
SUMMARY OF THE INVENTIONIn one aspect of the invention, a method is provided for assembling a structure on a support having a pattern of binding sites. In accordance with the method, a first fluid is provided on the surface of the support with the first fluid being of a type that that increases viscosity when cooled, the first fluid having first micro-components suspended therein each adapted to engage the binding sites. First fluid proximate to selected binding sites is cooled to increase the viscosity of the responsive fluid proximate to the selected binding sites so that the first micro-components suspended in the first fluid are inhibited from engaging the selected binding sites.
In another aspect of the invention, an apparatus is provided for assembling a micro-assembled structure on a support having binding sites thereon. The apparatus has a fluid source adapted to apply a first fluid having first micro-components therein onto the support, said first micro-components being adapted to engage the binding sites and said first fluid being of a type that increases viscosity when cooled; and a cooling applicator adapted to apply a cooled material to the support so that the support cools the first fluid to increase the viscosity of the first fluid proximate to the selected binding sites so that micro-components are inhibited from engaging the selected binding sites.
Support 60 has pattern of binding sites shown in
In operation, a thermally responsive fluid 72 is applied to support 60 (step 106). In the embodiments shown in FIGS. 2 and 3A-3B, this is done by flowing a thermally responsive fluid 72 across support 60. However, in other embodiments, thermally responsive fluid 72 can be applied to support 60 in other ways such as by immersing support 60 in a bath of thermally responsive fluid 72.
As used herein, the term thermally responsive fluid is used to mean a fluid that increases its viscosity upon cooling. Examples of useful thermally responsive fluids include, but are not limited to, aqueous solutions of polymers, polyelectrolytes, polyampholytes (e.g. gelatin solutions), gums, polysaccharides (e.g. gellan, carregeenan, and agarose) or combinations thereof that increase viscosity upon cooling. The useful range of any of these thermally responsive fluids depends on factors that can include the gel transition temperature required and that, in turn, depends upon the concentration of polymer, ionic strength, type of ions, pH, and molecular weight of polymer and the distribution of charged groups of the polymer. For example, a useful thermally-responsive solution includes an aqueous gelatin solution between 1-20% gelatin for a gelatin molecular weight of 120K Daltons.
Still other examples of a thermally responsive fluid include aqueous solutions 0.1 wt % or higher of agarose, 0.4 wt % gellan or higher. The gel transition temperature of these solutions is approximately 15 C.
In still other embodiments, a thermally responsive fluid can comprise solutions of any polymer that interacts with a colloid to form a thermally responsive liquid that gels upon cooling. For example, the thermally responsive fluid can comprise a mixture of gelatin and, for example, colloidal silicas such as Ludox® sold by W. R. Grace & Co., Davison Silica Products Division, East Chicago, Ill., U.S.A.
In yet another embodiment, a thermally responsive fluid can comprise an aqueous solution of xanthan gum with trivalent metal ions. For example, a gel transition temperature of between 25-75 C is achievable with 0.5 wt % xanthan combined with Aluminum ions as is described in A. B. Rodd et al., “Gel Point Studies For A Novel Biopolymer-crosslinker Gelling System”, Proceedings of the 13th International Congress on Rheology”, Cambridge, United Kingdom, Vol. 4, pp. 389, 2000.
The aqueous solutions described herein can include but are not limited to alcohols and polyethylene glycol. Non-aqueous solutions can also be used. For example, a thermally responsive fluid can be provided that incorporates chlorinated solvents and other non-aqueous solvents.
In application, thermally responsive fluid 72 is cooled in areas in and/or near selected binding sites on support 60, shown in the embodiment
Accordingly, as is shown in
A first type of micro-components 80 can include, but are not limited to, integrated circuits on silicon, nanowires, beads, rods, cubes, disks, buckey balls, capsules, electrophoretic beads, LEDs, light emitting materials, light reflecting materials, light absorbing materials, conductive materials, magnetic materials, dielectric materials, aerogels, biological cells, DNA and DNA derivatives, and DNA templated structures. A first type of micro-components 80 can be sized within any range of sizes that can effectively be suspended in solution in the thermally responsive fluid. In this regard, in selected embodiments, first type of micro-components 80 can be sized as small as 1 nanometer, and as large as several millimeters.
The first type of micro-components 80 are adapted to engage binding sites 62, 64, 66, and 68 as is known generally in the art described above. However, in the illustration of
After first type of micro-components 80 have been assembled to each of the non-selected binding sites 64 and 68, first carrier fluid 73 and any non-engaged first type of micro-components 80 are removed from first micro-assembled structure 100 (step 109). This can be done by mechanical action, by vacuum, or by rinsing, for example. In one embodiment, a liquid such as thermally responsive fluid 72 is rinsed over support 60 to remove any of the first type of micro-components 80 that remain on support 60 and that are not bound to one of binding sites 62, 64, 66 or 68. During removal of first slurry 70, cooling material 90 remains in contact with support 60 proximate to the selected binding sites 62 and 66 so that barrier zones 92 and 94 remain in place to prevent any non-engaged first type of micro-components 80 of the first type from binding to the selected sites 62 and 66 during removal of first slurry 70. The cooling material 90 can be removed from support to stop the cooling of support 60 proximate to binding sites 62 and 66 after removal of the first slurry 70 is complete (step 110). When cooling material 90 is removed from support 60, the temperature of support 60 increases and barrier zones 92 and 94 that are created as a result of such local temperature decreases also dissipate. A first micro-assembled structure 100 is formed as a result of the union of the first type of micro-components 80 with support 60. This first micro-assembled structure 100 can, in some embodiments such as the embodiment of
Additional micro-components can also be assembled to first micro-assembled structure 100. FIGS. 2B and 3A-3C illustrate on embodiment of a method for assembling more than one micro-component to a support. The embodiment of
When it is determined that only one further assembly step is necessary to create a final micro-assembled structure 104 (step 112), a final slurry 76 of carrier fluid 73 having a final type of micro-component 84 is applied to first micro-assembled structure 100 (step 115). This enables a final type of micro-components 84 to engage binding sites 62 and 66 and thus form a final micro-assembled structure 104 as illustrated in
When it is determined that more than two micro-assembly steps are to be performed (step 112), such as for example, where more than two different types of micro-components are to be joined to support 60, additional steps 118-122, shown in
Steps 111-122 can be repeated as necessary to permit many cycles of micro-assembly to occur, each with an additional application of an intermediate slurry 74 of a carrier fluid 73 bearing intermediate type micro-components 82 to a previously formed micro-assembled structure. In any of these additional steps, support 60 or intermediate micro-assembled structure 102 can be cooled as necessary to form barrier zones. When it is determined that only one further assembly step is to be performed (step 112) steps 113-117 are performed to yield a final micro-assembled structure 104 as shown in
As used herein, the first, intermediate, and final types of micro-components can comprise the same structures and can be different as necessary to permit formation of a heterogeneous micro-assembled structure.
Cooling of SupportThe steps of cooling support 60 (steps 107, 114, and 119) can be performed in a variety of ways. As noted above, the thermally responsive fluid 72 is cooled indirectly by applying a cooling material 90 to support 60 or to some component of support 60 so that support 60 cools thermally responsive fluid 72. A cooling member 91 is typically used to perform this function, in various embodiments described herein. In particular, as will be described in greater detail below, cooling member 91 can comprise a pattern cooler or pattern roller that moves a cooled structure to apply a cooling material 90 to support 60. In other embodiments cooling member 91 can comprise a source of a cooling material in the form of a fluid such as a liquid or a gas and a nozzle to controllably deliver the fluid cooling member 91 to support 60. In still other embodiments cooling member 91 can comprise a control system for selectively electrical signals that actuate coolers in support 60.
In certain embodiments, a cooling material 90 is broadly applied to support 60 using, for example, a cooling plate or other surface of cooling material 90 and support 60 is adapted to react this in a selective way, and to thereby selectively cool the thermally responsive fluid 72. In other embodiments, cooling material 90 is selectively applied to selectively cool support 60 and to thereby selectively cool thermally responsive fluid 72.
Coolers 132, 134, 136, and 138 can comprise any of a variety of forms. In the example shown in
In any of
It will be appreciated that cooling liquid 141, such as acetone or methylene chloride, can be applied patternwise to the surface of a support 60.
It will also be appreciated that cooling material 90 can similarly be applied to support 60 in a fluidic form such as a liquid or gaseous form. For example, a liquid cooling material 90 can be applied to support 60 uniformly or it can be applied in a pattern-wise fashion using among other things printing, drop on demand ink jet technology, masking, continuous ink jet technology, or printing technologies that use super critically cooled carbon dioxide as a solvent to deliver materials such as cooling material 90.
Cooling material 90 can be applied to support 60 before thermally responsive fluid 72 is introduced and when applied in this fashion, cooling material 90 can be applied directly to a side of support 60 having binding sites on support 60 or cooling material 90 can be applied to an opposite side. Where cooling material 90 is applied to support 60 before introduction of thermally responsive fluid 72, cooling material 90, support 60 and or coolers such as coolers 132, and 134 can be provided that ensure that any binding sites that are to be protected by a barrier zone will be cooled in a manner that does not allow the barrier zone to dissipate while a first slurry 70 having micro-components is applied to support 60. Coolers 132 and 134 can be specially adapted for such a controlled cooling response.
In
It will be appreciated that, in certain embodiments of the invention, it is not necessary to introduce a second cooling material, and that in such embodiments, the flow of first slurry 70 will be timed to occur during a time when an initial amount of cooling sufficient to cause formation of barrier zones 92, 94, and 98 at binding sites 62, 64, and 66, while the introduction of second intermediate slurry 74 can be timed to occur at a time after the cooling supplied by less efficient coolers 132 and 136 has diminished sufficiently to allow barrier zones 92 and 98 to dissipate, at the less efficient coolers 132 and before the cooling supplied by more efficient cooler 134 has diminished sufficiently to allow barrier zone 94 to dissipate. Similarly, in this embodiment, a final slurry can be introduced after the cooling supplied by more efficient cooler 134 has diminished sufficiently to allow barrier zone 94 to dissipate.
Discrimination can be conferred upon binding sites by making at least two types of coolers with differing thermal absorption characteristics or differing thermal release characteristics.
Specifically, discrimination is accomplished in this embodiment by using an arrangement of coolers having different sizes to selectively control the thermal cooling that cooler 134 can provide as compared to coolers 132 and 136. This limits the rate and/or amount of cooling that can be thermally provided to thermally responsive fluid 72 in a slurry to produce a barrier zone. The spatial distribution of area cooled by coolers 132, 134, and 136 into cooler regions of the slurry determines the profile of reduced temperature areas surrounding each coolers 132, 134, and 136. Sufficient exposure cooling material 90 can cause a coolers 132, 134, and 136 to produce a barrier beyond the lateral extent of cooler 132, 134, and 136.
It will be appreciated that such a contact cooler 148 can take many forms. For example, a cooling block 150 of the type shown in
After support 60 has been cooled, support 60 is passed through a first bath 165. First bath 165 contains thermally responsive fluid 72. As thermally responsive fluid 72 is cooled by support 60, barrier zones are formed as described above. Support 60 with certain sites blocked by the barrier zones is passed through a first slurry bath 166. Alternatively, support 60 can be cooled as it is passed through first bath 165 as described above.
First slurry bath 166 contains a first slurry 70 having micro-components, such as first type of micro-components 80, within carrier fluid 73 such as thermally responsive fluid 72. The barrier zones inhibit the first type of micro-components 80 from engaging selected binding sites. A first type of micro-components 80, engage binding sites not protected by barrier zones to form a micro-assembled structure 100. As support 60 continues to move through the system 158 shown in
The web of support 60 then passes over at least one intermediate roller 170. In the embodiment shown, intermediate roller 170 comprises another thermal transfer roller that is adapted to receive pattern of chilled areas 90a from an intermediate pattern cooler 172 and to selectively cool web of support 60. After support 60 has been cooled support 60 is passed through an intermediate slurry bath 174. Intermediate slurry bath 174 has a carrier fluid 73, comprising in this embodiment, a thermally responsive fluid 72 containing intermediate type of micro-components 82. Intermediate type of micro-components 84, are then permitted engage binding sites on micro-assembled structure 100 to form an intermediate micro-assembled structure 102. The type of thermally responsive fluid 72 used in the intermediate slurry bath 174 can be the same as or can be different than the type of thermally responsive fluid used in carrier fluid that is used in the first slurry bath 166.
As thermally responsive fluid 72 cooled by support 60, barrier zones are formed as described above. These barrier zones inhibit intermediate type of micro-components 84 from engaging selected binding sites. Intermediate type of micro-components 84 engage binding sites not protected by barrier zones to form a micro-assembled structure 100. As support 60 continues to move through the system 158 shown in
Web of support 60 then passes over final roller 180. In the embodiment shown, final roller 180 comprises another thermal transfer roller that is adapted to receive pattern of chilled areas 90a from a final pattern cooler 182 and to selectively cool web of support 60. After support 60 has been cooled by final roller 180, web of support 60 is passed through a final slurry bath 184. Final slurry bath 184 contains at least one final type of micro-components 86 within a carrier fluid 73 such as thermally responsive fluid 72. It will be appreciated however that the thermally responsive fluid 72 can be used in the intermediate slurry bath 184 can be the same as or can be different than the carrier fluid that is used in the first slurry bath 166 or in the second intermediate slurry bath 174.
As thermally responsive fluid 72 is cooled by support 60, barrier zones are formed as described above. These barrier zones inhibit the final type of micro-components 86 from engaging selected binding sites. Intermediate type of micro-components 84, engage binding sites not protected by barrier zones, to form a final micro-assembled structure 104. As support 60 continues to move through the system 158 shown in
It will be appreciated that once a pattern of energy is transferred to support 60, “cool spots” are formed on support 60 that have a finite lifetime because they are heated by their surroundings. A cool spot is heated at a rate that depends primarily on the temperature difference between the cool spot and its surroundings including the thermally responsive fluid 72. In order to prolong the lifetime of a hot spot, a thermally responsive fluid 72 may be advantageously supplied at a temperature slightly above a transition temperature at which the viscosity of the thermally responsive carrier fluid 72 undergoes meaningful change or transition of viscosity, such as a transition temperature at which thermally responsive carrier fluid 72 transitions from a liquid to a gel so as to minimize the amount of cooling required to form a barrier zone 92 while at the same time reducing the temperature difference between the chilled spot and its surroundings.
Another embodiment that selectively cools a support 60 to form barrier zones corresponding to selected binding sites on a support, is shown in
Alternatively, any of the patterned coolers 164, 172, or 182 can also comprise an array of electrically addressable cooling elements. For example, a typical array of electrically addressable cooling elements for use in the method of the present invention contains a plurality of adjacent, microscopic Peltier type cooling elements, which convert electrical energy via a joule effect into a cooling effect. Such thermal heads can be used in contact or, in close proximity with support 60 so as to transfer heat from support 60 to cool support 60 in a pattern-wise fashion as support 60 passes across a thermal transfer roller such as first roller 162, intermediate roller 170, or final roller 180.
In still other embodiments, any of pattern coolers 164, 172, and 182 can be provided across a path of movement comprise a linear array cooler elements disposed across a pathway used by support 60 such as an array of Peltier type coolers, or another array of coolers. It will be appreciated that the methods described with respect FIGS. 7 and 8A-8B can also be performed in a non-continuous process. For example, as is shown in
However, in another embodiment shown in
In another embodiment, individual sheets of support 60 can be passed through any of the above-described embodiments of an apparatus 158 for forming a micro-assembled structure without platens 190. For example, the individual sheets can be passed through apparatus 158 using any known conveyor system including but not limited to a belt drum or other conveying system.
Referring to
A first slurry bath 166 applies first slurry 70 of carrier fluid 73 having red micro-beads 230 to support 60. When the first slurry bath 166 is applied, red micro-beads 230 bind to red micro-cup sites 214.
In this way a first micro-assembled structure 100 is formed. Micro-assembled structure 100 is then rinsed in a rinsing device 168 to remove any residual unbound red micro-beads 230. The energy that allowed the formation of barrier zones 92 and 94 is then removed or allowed to dissipate so that other barrier zones can be subsequently applied to first micro-assembled structure 100.
In the embodiment shown, after red micro-beads 230 are removed from first micro-assembled structure 100, a new pattern of chilled areas formed on first micro-assembled structure 100 and first micro-assembled structure 100 is exposed in an intermediate slurry bath 174 having, in this embodiment, intermediate micro-components comprising green micro-beads 232 in a thermally responsive fluid 72 causing the formation of intermediate barrier zone 96 proximate to blue micro-cup sites 218 as is shown on
Green micro-beads 232 are barred from engaging red micro-cup sites 214 because red micro-cup sites 214 are occupied by red micro-beads 230 and are also barred from engaging blue micro-cup sites 218 because blue micro-cup sites 218 are shielded by barrier zone 96. Accordingly, as is shown in
As is also shown in
A final slurry bath 184 applies a final slurry 76, having blue micro-beads 234 and a carrier fluid 73, to intermediate micro-assembled structure 102. Blue micro-beads 234 are blocked from engaging red micro-cup sites 214, and green micro-cup sites 216 as they are occupied by, respectively, red micro-beads 230 and green micro-beads 232. Accordingly, as is shown in
In any embodiment of the invention, cooling of a thermally responsive fluid can be performed at any time before or during an assembly process and/or before or during a rinsing process so long as the cooling is performed under circumstances that will allow the formation of barrier zones while there is a meaningful risk that micro-components will be positioned to engage the binding sites. Thus, for example in the embodiment of
In various illustrations shown above, barrier zones 92, 94, and 96 have been shown having shapes defined for illustrative purposes and these shapes are not limiting. It is sufficient that a barrier zone provide only the minimum resistance to the binding of micro-components to a selected binding site to inhibit such binding. For example, in certain embodiments, a partial blockage of a binding site can be sufficient. In another example, where ligands or other biological binding sites are used, it can be sufficient merely to block or mask the receptor sites of the ligand.
Further, in the embodiments illustrated above, barrier zones have been shown as being provided only for open binding sites that do not have micro-components bound thereto. This too is not limiting and the invention can be practiced in a manner that allows the formation of barrier zones proximate to binding sites that are occupied by micro-components.
This can be done, for example, to protect such micro-components from damage during subsequent assembly steps.
It will further be appreciated that the terms cool, cooling and selectively cooling as used in the present invention are relative measures of a temperature gradient that exists on the support 60. In this regard areas that are described as being cooled in accordance with the method herein can be provided by applying heat other areas of the support, so that the selected areas for cooling will be cool relative to the elevated temperatures of other portions of the support.
The invention has been described in detail with particular reference to certain preferred embodiments thereof, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention.
PARTS LIST
- 10 substrate
- 21 binding sites in the form of recesses
- 22 binding site
- 23 binding site
- 24 binding site
- 25 binding site
- 27 electrodes
- 29 fluid
- 32 drops
- 34 liquid
- 36 surface
- 47 micro-components
- 48 hydrophobic surfaces
- 49 micro-components
- 51 micro-components
- 52 micro-component
- 53 magnetic surface
- 55 oppositely charged micro-components
- 60 support
- 62 binding site
- 64 binding site
- 66 binding site
- 68 binding site
- 70 first slurry
- 72 thermally responsive fluid
- 73 carrier fluid
- 74 intermediate slurry
- 76 final slurry
- 80 first type of micro-component(s)
- 82 intermediate type of micro-component(s)
- 84 intermediate type of micro-component(s)
- 86 final type of micro-component(s)
- 88 liquid engagement surface
- 90 cooling material
- 90a pattern of chilled areas
- 90b pattern of cooled areas
- 91 cooling member
- 92 barrier zone
- 94 barrier zone
- 96 barrier zone
- 98 barrier zone
- 100 micro-assembled structure
- 102 intermediate micro-assembled structure
- 104 final micro-assembled structure
- 105 provide support step
- 106 provide carrier fluid step
- 107 cool carrier fluid step
- 108 apply first slurry step
- 109 remove first slurry step
- 110 discontinue cooling step
- 111 further assembly determining step
- 112 last assembly determining step
- 113 apply thermally responsive fluid step
- 114 cool thermally responsive fluid step
- 115 applied final slurry step
- 116 remove thermally responsive fluid step
- 117 discontinue cooling step
- 118 apply thermally responsive fluid step
- 119 cool step
- 120 apply intermediate slurry step
- 121 remove intermediate slurry step
- 122 discontinue cooling step
- 132 cooler
- 134 cooler
- 136 cooler
- 138 cooler
- 140 liquid
- 141 liquid cooler
- 142 cooler
- 143 inductor
- 144 capacitor
- 145 inductor
- 146 cooler
- 147 capacitor
- 148 contact cooler
- 150 cooling block
- 152 projections
- 154 selectively addressable actuators
- 156 selectively actuatable cooler
- 158 apparatus for assembling a micro-assembled structure
- 160 supply
- 162 first roller
- 164 first pattern cooler
- 165 first bath containing thermally responsive carrier liquid
- 166 first slurry bath
- 168 rinsing device
- 170 intermediate roller
- 172 intermediate pattern cooler
- 173 intermediate fluid bath
- 174 intermediate slurry bath
- 176 intermediate rinsing device
- 180 final roller
- 182 final pattern cooler
- 183 final fluid bath
- 183a, b, c laser thermal printhead
- 184 final slurry bath
- 185a, b, c channels
- 186 final rinsing device
- 188 post-assembly processing station
- 190 platen(s)
- 191 roller
- 192 top surface of platen
- 139a cooler
- 139b cooler
- 194 top surface of platen
- 196 top surface of platen
- 198 back surface of platen
- 200 back surface of platen
- 202 back surface of platen
- 206 patterned contact cooler
- 210 micro-cup sites
- 212 section
- 214 red micro-cup sites
- 216 green micro-cup sites
- 218 blue micro-cup sites
- 220 post-assembly processing station
- 230 red micro-beads
- 232 green micro-beads
- 234 blue micro-beads
Claims
1. An apparatus for assembling a micro-assembled structure on a support having binding sites thereon, the apparatus comprising:
- a fluid source adapted to apply a first fluid having first micro-components therein onto the support, said first micro-components being adapted to engage the binding sites and said first fluid being of a type that increases viscosity when cooled; and
- a cooling applicator adapted to apply a cooling material to the support so that the support cools the first fluid to increase the viscosity of the first fluid proximate to the selected binding sites so that micro-components are inhibited from engaging the selected binding sites.
2. The apparatus of claim 1, wherein the fluid source is adapted to apply the first fluid in a first time period and to introduce micro-components into the first fluid at a second, later, time period after the viscosity of the first fluid proximate to the selected binding sites has been increased.
3. The apparatus of claim 2, further comprising a cleaning system adapted to remove the first fluid and any non-engaged first micro-components from the support.
4. The apparatus of claim 3, further comprising a second fluid source adapted to apply a second fluid having second micro-components therein onto the support, said second micro-components being adapted to engage the binding sites.
5. The apparatus of claim 1, further comprising a cooling pattern comprising at least one contact adapted to engage the support and operatively associated with coolant so that energy can flow from areas of the support that are proximate to selected binding sites to the coolant.
6. The apparatus of claim 5, wherein the cooling pattern has addressable actuators to move selected chilled contacts from a pattern of chilled projections into contact with the support, to selectively cool the support in areas proximate to the selective binding sites.
7. The apparatus of claim 1, wherein the cooling apparatus comprises a chilled pattern roller.
8. The apparatus of claim 1, further comprising source of a coolant fluid and at least one nozzle adapted to controllably deliver coolant fluid to the support proximate to the selected binding sites.
9. An apparatus for assembling a structure using a support having binding sites thereon, the apparatus comprising:
- a means for providing onto the support a first fluid of a type that increases viscosity when cooled;
- a means for selectively cooling the first fluid proximate to selected binding sites; and
- a means for exposing the support to a first slurry of a carrier fluid having a first type of micro-components therein, so that the first type of micro-components can engage the non-selected binding sites.
10. The apparatus of claim 9, further comprising a means for removing the first type of micro-components and a means for disabling the means for selectively cooling the first thermally responsive fluid proximate to selected binding sites so that the increases in the viscosity of the fluid proximate to the binding sites can be dissipated.
Type: Application
Filed: Jan 26, 2010
Publication Date: May 20, 2010
Inventors: Ravi Sharma (Fairport, NY), Charles P. Lusignan (Rochester, NY)
Application Number: 12/693,664