Highly flexible near-infrared metamaterials
A novel multilayer flexible metamaterial that can work at near infrared (NIR) regime that can be fabricated on transparent PET substrate using flip chip transfer (FCT) technique. An embodiment of the present invention also provides novel NIR metamaterial device that can be transformed into various shapes by bending the PET substrate, wherein said metamaterial device is tunable via physical manipulation of its flexible substrate with no requirement to change the material composition of the substrate. The flexibility allows the novel NIR metamaterial device to bend and stretch, which can alter the device structure. Since the resonant frequency of each device is a function of the device structure, the resonant frequency can be tuned by the bend and stretch of the substrate. Another embodiment of the present invention further provides novel tunable sensors and emitters using such flexible metamaterials and devices.
1. A metamaterial comprising:
a multi-layer comprising at least:
a first conductor layer,
an insulator layer,
a second conductor layer; and
a flexible substrate;
wherein the multi-layer is transferred from a rigid substrate to the flexible substrate using a solution-free flip chip transfer (FCT) technique;
wherein the solution-free FCT technique comprising:
attaching a double-sided optically clear adhesive on the flexible substrate,
placing the multi-layer in intimate contact with the optically clear adhesive, and
peeling the multi-layer off from the rigid substrate; and
wherein the metamaterial having a range of operating frequencies including near infrared.
2. A metamaterial according to claim 1 , wherein the flexible substrate being permeable to electromagnetic radiation of frequencies including visible light.
3. A metamaterial according to claim 1 , wherein the range of frequencies of the metamaterial can be adjusted by physically manipulating the flexible substrate.
4. A metamaterial according to claim 1 , wherein the metamaterial can be transformed into arbitrary shaped devices by physical manipulation of the flexible substrate.
5. A tunable receiver device made from the metamaterial according to claim 1 , wherein the tunable receiver being one or more of:
electromagnetic wave sensors,
electromagnetic wave absorbers, and
electromagnetic wave receivers.
6. A tunable transmitter device made from the metamaterial according to claim 1 , wherein the transmitter device being one or more of:
electromagnetic wave emitters,
electromagnetic wave transmitters, and
electromagnetic wave reflectors.
7. The metamaterial according to claim 1 , wherein the rigid substrate is coated with a thin native oxide film which allows the multi-layer being peeled off from the thin native oxide film coated rigid substrate and possessing sufficient flexibility to be bended into various shapes when the multi-layer is transferred to the flexible substrate.
8. The metamaterial according to claim 7 , wherein the thin native oxide film being chromium thin film and exposed to air to become oxidized.
9. The metamaterial according to claim 1 , wherein the multi-layer is sandwiched between the optically clear adhesive and the rigid substrate prior to completing the transfer to the flexible substrate.
10. The metamaterial according to claim 1 , wherein the rigid substrate being glass, quartz, metal, or any combination thereof.
11. The metamaterial according to claim 1 , wherein said flexible substrate being plastic, polymer film, polyethylene terephthalate, or any combination thereof.
12. The metamaterial according to claim 1 , wherein the metamaterial and optical adhesive are encapsulated by spin-coating a polymethyl methacrylate (PMMA) layer after transferring said metamaterial to said flexible substrate.
13. The metamaterial according to claim 1 , wherein the multi-layer comprising:
a gold layer,
an ITO layer, and
a plurality of gold discs;
wherein the ITO layer is located on said gold layer, the plurality of gold discs are located on said ITO layer; and
wherein each of the plurality of the gold discs has a diameter of approximately 320 to 360 nm and said plurality of gold discs has a disc period of approximately 600 to 910 nm.
14. The metamaterial of claim 13 , wherein each of said plurality of the gold discs has a thickness of approximately 50 nm; said ITO layer has a thickness of approximately 50 nm; said gold layer has a thickness of approximately 50 nm.