Layered photonic crystals
View Patent ↗A three dimensional photonic crystal and layer-by-layer processes of fabricating the photonic crystal. A substrate is exposed to a plurality of first microspheres made of a first material, the first material being of a type that will bond to the templated substrate and form a self-passivated layer of first microspheres to produce a first layer. The first layer is exposed to a plurality of second microspheres made of a second material, the second material being of a type that will bond to the first layer and form a self-passivated layer of second microspheres. This layering of alternating first and second microspheres can be repeated as desired to build a three dimensional photonic crystal of desired geometry. Charged polymers such as polyelectrolyte coatings can be used to create the bonds.
1. A method of fabricating a photonic crystal, comprising:
providing a substrate;
exposing the substrate to a plurality of first microspheres made of a first material, the first material being of a type that will bond to the substrate and form a self-passivated layer of first microspheres to produce a first layer; and
exposing the first layer to a plurality of second microspheres made of a second material, the second material being of a type that will bond to the first layer and form a self-passivated second layer of second microspheres.
2. The method according to claim 1 , further comprising:
exposing the second layer to a plurality of the first microspheres made of a the first material, the first material being of a type that will bond to the second layer and form a self-passivated layer of first microspheres.
3. The method according to claim 2 , further comprising:
repeatedly exposing a most recently formed layer to microspheres to a plurality of microspheres that will bond to the most recently formed layer and self-passivate to fabricate a multiple layer photonic crystal.
4. The method according to claim 1 , wherein the first microspheres comprise streptavidin-coated microspheres and the second microspheres comprise biotin coated microspheres.
5. The method according to claim 4 , wherein the substrate has biotinylated regions on a surface of the substrate.
6. The method according to claim 1 , wherein the first microspheres comprise biotin-coated microspheres and the second microspheres comprise streptavidin-coated microspheres.
7. The method according to claim 1 , wherein the bond comprises at least one of covalent bonding, electrostatic attraction, metallic bonding, hydrogen bonding, Van der Waals forces, hydrophobic/hydrophilic attractions and biological recognition.
8. The method according to claim 1 , wherein one of the first and second microspheres have DNA strands on a surface thereof, and wherein the other of the first and second microspheres have at least one of complimentary DNA strands, complimentary RNA strands, oligonucleotides and DNA binding proteins on a surface thereof.
9. The method according to claim 1 , wherein one of the first and second microspheres have RNA strands on a surface thereof, and wherein the other of the first and second microspheres have at least one of complimentary DNA strands, complimentary RNA strands, oligonucleotides and DNA binding proteins on a surface thereof.
10. The method according to claim 1 , wherein one of the first and second microspheres have a protein situated on a surface thereof, and wherein the other of the first and second microspheres have at least one of an antigen and a ligand that bonds to the protein on a surface thereof.
11. The method according to claim 1 , wherein the first microspheres have a first molecule with a first endgroup on a surface thereof, and wherein the second microspheres have a second molecule with a second endgroup on a surface thereof, wherein the first and second molecules bond to each other, but not to themselves, by formation of one of a covalent, ionic, metallic, hydrogen and Van der Waals bond.
12. The method according to claim 1 , wherein one of the first and second microspheres have a bulk electrostatic charge or a surface electrostatic charge of a first charge state, and wherein the other of the first and second microspheres have a second bulk electrostatic charge or surface electrostatic charge with a second charge state which is opposite and attractive to the first charge state, wherein the first and second microspheres bond to each other by formation of ionic/electrostatic bonds, but do not bond to themselves.
13. The method according to claim 1 , further comprising processing the first layer to form a surface that will bond to the second microspheres prior to exposing the first layer to the plurality of microspheres.
14. The method according to claim 1 , wherein the substrate has a surface charge of a first polarity and wherein the first microspheres have a charge of a second polarity, and wherein the second microspheres have a charge of the first polarity.
15. The method according to claim 1 , wherein the first and second microspheres are coated with first and second polyelectrolyte layers, wherein the first and second polyelectrolyte layers have opposite charge.
16. A method of fabricating a photonic crystal, comprising:
a) providing a substrate;
b) exposing the substrate to a plurality of first microspheres made of a first material, the first material being of a type that will bond to the substrate and form a self-passivated layer of first microspheres to produce a layer of microspheres;
c) modifying the first layer of microspheres to permit the first layer of microspheres to bond with other microspheres to thereby produce a bondable layer; and
d) exposing the bondable layer to a plurality of second microspheres to form a second layer of microspheres.
17. The method according to claim 16 , wherein the plurality of second microspheres are made of the first material.
18. The method according to claim 16 , wherein the plurality of second microspheres are made of a second material.
19. The method according to claim 16 , further comprising:
modifying the second layer of microspheres to permit the second layer of microspheres to bond with other microspheres and thereby produce a second bondable layer;
exposing the second bondable layer to a plurality of microspheres to form a third self-passivated layer of microspheres to produce a three layer photonic crystal.
20. The method according to claim 16 , further comprising repeating c) and d) a plurality of times to achieve a desired number of layers of a photonic crystal.
21. The method according to claim 16 , wherein the bond comprises at least one of covalent bonding, electrostatic attraction, metallic bonding, hydrogen bonding, Van der Waals forces, hydrophobic/hydrophilic attractions and biological recognition.
22. The method according to claim 16 , further comprising activating the bond of the microspheres by at least one of the following: addition of additive chemicals such as glutaraldehyde, by change in pH, and by exposure to radiation.
23. The method according to claim 16 , wherein the first microspheres have a first charge, and wherein the modifying comprises coating the first microspheres with a polyelectrolyte film having charge opposite the first charge.
24. The method according to claim 23 , wherein the second microspheres also have the first charge.
25. A photonic crystal structure, comprising:
a substrate processed to bond preferentially in selected areas;
a first layer of first microspheres, the first layer being one microsphere deep, the first microspheres comprising a first material having a first coating and wherein the first coated microspheres are bonded to the selected areas of the substrate;
a second layer of second microspheres one microsphere deep and bonded to the first layer of microspheres, the second microspheres having a second coating; and
wherein the first and second coatings bond to each other but not to themselves.
26. The apparatus according to claim 25 , wherein one of the first and second microspheres comprise streptavidin-coated microspheres and the other of the first and second microspheres comprise biotin coated microspheres.
27. The apparatus according to claim 25 , wherein one of the first and second microspheres have RNA strands on a surface thereof, and wherein the other of the first and second microspheres have at least one of complimentary DNA strands, complimentary RNA strands, oligonucleotides and RNA binding proteins on a surface thereof.
28. The apparatus according to claim 25 , wherein the one of the first and second microspheres have DNA strands on a surface thereof, and wherein the other of the first and second microspheres have at least one of complimentary DNA strands, complimentary RNA strands, oligonucleotides and DNA binding proteins on a surface thereof.
29. The apparatus according to claim 25 , wherein one of the first and second microspheres have a protein situated on a surface thereof, and wherein the other of the first and second microspheres have at least one of an antigen and a ligand that bonds to the protein on a surface thereof.
30. The apparatus according to claim 25 , wherein first microspheres have a first molecule on a surface thereof, and wherein the second microspheres have a second molecule on a surface thereof, wherein the first and second molecules bond to each other but not to themselves.
31. The apparatus according to claim 25 , wherein the substrate comprises an untemplated substrate.
32. The apparatus according to claim 25 , wherein the bond comprises at least one of covalent bonding, electrostatic attraction, metallic bonding, hydrogen bonding, Van der Waals forces, hydrophobic/hydrophilic attractions and biological recognition.
33. The apparatus according to claim 25 , wherein the second microspheres are comprised of a second material.
34. The apparatus according to claim 25 , wherein the second microspheres are comprised of the first material.
35. The apparatus according to claim 25 , wherein the substrate has a surface charge of a first polarity and wherein the first coating on the first microspheres have a charge of a second polarity, and wherein the second coating on the second microspheres have a charge of the first polarity.
36. The apparatus according to claim 25 , wherein the first and second microspheres are coated with first and second polyelectrolyte layers, wherein the first and second polyelectrolyte layers have opposite charge.
37. A method of fabricating a photonic crystal, comprising:
providing a substrate;
providing a plurality of first microsoheres having a first coating;
bonding a single layer of the first microspheres one microsphere deep to the substrate to form a first layer;
providing a plurality of second microspheres having a second coating, wherein the first and second coatings bond to each other but not to themselves; and
bonding a single layer of second microspheres one microsphere deep to the first layer to form a second layer.
38. The method according to claim 37 , further comprising repeatedly bonding alternating layers of first and second microspheres microspheres one microsphere deep to produce a multiple layer photonic crystal.
39. The method according to claim 37 , wherein the bond comprises at least one of covalent bonding, electrostatic attraction, metallic bonding, hydrogen bonding, Van der Waals forces, hydrophobic/hydrophilic attractions and biological recognition.
40. The method according to claim 37 , wherein the substrate comprises an untemplated substrate.
41. The method according to claim 37 , wherein alternating layers of the multiple layer photonic crystal are comprised of microspheres of differing types.
42. The method according to claim 37 , wherein the substrate has a surface charge of a first polarity and wherein the first microspheres have a charge of a second polarity, and wherein the second microspheres have a charge of the first polarity.
43. The method according to claim 37 , wherein the first and second coatings comprise first and second polyelectrolyte layers, wherein the first and second polyelectrolyte layers have opposite charge.
44. A method of fabricating a photonic crystal, comprising:
providing a templated substrate having a first charge; and
exposing the templated substrate to a plurality of first microspheres having a polyelectrolyte coating carrying a second charge, the second charge being opposite the first charge so that the plurality of first microspheres will bond to the templated substrate and form a self-passivated layer of first microspheres to produce a first layer.
45. The method according to claim 44 , further comprising:
exposing the first layer to a plurality of second microspheres having a polyelectrolyte coating carrying the second charge in order to bond to the first layer and form a self-passivated second layer of second microspheres.
46. The method according to claim 45 , further comprising:
exposing the second layer to a plurality of the first microspheres having a polyelectrolyte coating carrying the first charge in order to bond to the second layer and form a self-passivated layer of first microspheres.
47. The method according to claim 46 , further comprising:
repeatedly exposing a most recently formed layer to microspheres to a plurality of microspheres coated with a charged polyelectrolyte coating that will bond to the most recently formed layer and self-passivate to fabricate a multiple layer photonic crystal.
48. The method according to claim 47 , wherein a last layer comprises carboxylated microspheres.
49. The method according to claim 45 , wherein the first and second microspheres are coated with one of Poly(sodium 4 styrenesulfonate) and Poly(diallyldimethylammonium chloride).
50. A method of fabricating a photonic crystal, comprising:
a) providing a templated substrate;
b) exposing the templated substrate to a plurality of first microspheres made of a first material, the first material being of a type that will bond to the templated substrate and form a self-passivated layer of first microspheres to produce a layer of microspheres;
c) modifying the first layer of microspheres to permit the first layer of microspheres to bond with other microspheres to thereby produce a bondable layer by coating the first microspheres with a polyelectrolyte film having a first charge; and
d) exposing the bondable layer to a plurality of second microspheres having charge opposite the first charge to form a second layer of microspheres.
51. The method according to claim 50 , further comprising:
modifying the second layer of microspheres to permit the second layer of microspheres to bond with other microspheres and thereby produce a second bondable layer by coating the second layer with a polyelectrolyte film;
exposing the second bondable layer to a plurality of microspheres to form a third self-passivated layer of microspheres to produce a three layer photonic crystal.
52. The method according to claim 51 , further comprising repeating c) and d) a plurality of times to achieve a desired number of layers of a photonic crystal.
53. The method according to claim 50 , wherein the first and second microspheres are coated with one of Poly(sodium 4 styrenesulfonate) and Poly(diallyldimethylammonium chloride).
54. A photonic crystal structure, comprising:
a templated substrate processed to bond preferentially to a first material in selected areas;
a first layer of first microspheres, the first layer being one microsphere deep, the first microspheres comprising the first material and bonded to the selected areas of the templated substrate; and
a charged polymer coating on the first microspheres.
55. The apparatus according to claim 54 , further comprising a second layer of second microspheres one microsphere deep and bonded to the first layer of microspheres, the second microspheres having a charge that bonds to the charged polymer coating.
56. The apparatus according to claim 54 , wherein the charged polymer comprises a polyelectrolyte.
57. The method according to claim 56 , wherein the charged polymer comprises one of Poly(sodium 4 styrenesulfonate) and Poly(diallyldimethylammonium chloride).
58. A method of fabricating a photonic crystal, comprising:
providing a templated substrate;
bonding a single layer of charged polymer coated microspheres one microsphere deep to the templated substrate to form a first layer; and
bonding a single layer of charged polymer coated microspheres one microsphere deep to the first layer to form a second layer.
59. The method according to claim 58 , further comprising repeatedly bonding a layer of charged polymer coated microspheres one microsphere deep to a most recently formed layer to produce a multiple layer photonic crystal.
60. The apparatus according to claim 58 , wherein the charged polymer comprises a polyelectrolyte.
61. The method according to claim 60 , wherein the charged polymers are selected from Poly(sodium 4 styrenesulfonate) and Poly(diallyldimethylammonium chloride).
62. A method of fabricating a photonic crystal, comprising the ordered steps of:
a. providing a plurality of charged polymer coated microspheres;
b. bonding a single layer of the charged polymer coated microspheres one microsphere deep to a substrate to form a first layer; and
c. bonding a single layer of the charged polymer coated microspheres one microsphere deep to the first layer to form a second layer.
63. The method according to claim 62 , further comprising repeatedly bonding a layer of charged polymer coated microspheres one microsphere deep to a most recently formed layer to produce a multiple layer photonic crystal.
64. The apparatus according to claim 62 , wherein the charged polymer comprises a polyelectrolyte.
65. The method according to claim 64 , wherein the charged polymers are selected from Poly(sodium 4 styrenesulfonate) and Poly(diallyldimethylammonium chloride).