Highly wrinkled metal thin films using lift-off layers

Patent metadata

Field	Value
Publication number	US-10780688-B2
Application number	US-201715436324-A
Country	US
Kind code	B2
Filing date	Feb 17, 2017
Priority date	Feb 17, 2016
Publication date	Sep 22, 2020
Grant date	Sep 22, 2020

Abstract

Described are fabrication methods of highly wrinkled metal thin films for applications in electronics such as wearable devices, strain sensors, and capacitive sensors.

First claim

What is claimed is:

1. A sensor component assembly comprising:
a shape memory polymer layer comprising a first polymer;
a lift-off layer disposed on the shape memory polymer layer, wherein the lift-off layer comprises a material that is different from the first polymer in the shape memory polymer layer; and
a conductive layer;

wherein the shape memory polymer layer is capable of being shrunken by an amount sufficient to induce wrinkles in the conductor layer, and
wherein the lift-off layer comprises a material that is susceptible to dissolution by acetone and the shape memory layer is resistant to dissolution by acetone; or the lift-off layer comprises a material that is susceptible to dissolution by anisole and the shape memory layer is resistant to dissolution by anisole.

2. The sensor component assembly of claim 1 , wherein the material in the lift-off layer comprises a second polymer that is different from the first polymer in the shape memory polymer layer.

3. The sensor component assembly of claim 2 , wherein the second polymer in the lift-off layer comprises poly(methyl methacrylate).

4. The sensor component assembly of claim 1 , wherein the conductive layer comprises a metal.

5. The sensor component assembly of claim 1 , further comprising a stretchable layer disposed over a side of the conductive layer opposite the lift-off layer.

6. The sensor component assembly of claim 4 , wherein the metal comprises gold.

7. The sensor component assembly of claim 1 , wherein the shape memory polymer layer comprises a polyolefin and the lift-off layer comprises poly(methyl methacrylate).

8. The sensor component assembly of claim 1 , wherein the lift-off layer has a thickness of about 100 nm.

9. A method of forming a sensor component comprising:
obtaining the sensor component assembly of claim 1 ,
shrinking the sensor component assembly by baking beyond a glass transition temperature of the shape memory polymer, wherein the conductive layer becomes wrinkled,
coating a stretchable layer on the conductive layer, opposite the lift-off layer, and removing the lift-off layer,

wherein the sensor component comprises the wrinkled conductive layer and the stretchable layer.

10. The method of claim 9 , wherein the conductive layer comprises gold.

11. The method of claim 9 , wherein the stretchable layer comprises a silicone layer.

12. The method of claim 11 , wherein the silicone layer comprises a thickness of 100-1000 μm.

13. The method of claim 9 , further comprising, prior to coating the stretchable layer on the conductive layer, treating a surface of the conductive layer to enhance adhesion thereof to the stretchable layer.

14. The method of claim 9 , wherein the material in the lift-off layer comprises a second polymer that is different from the first polymer in the shape memory polymer layer, and wherein removing the lift-off layer comprises exposing the second polymer of the lift-off layer to a solvent to dissolve away the second polymer.

15. The method of claim 14 , wherein the solvent is in a vapor state.

16. The method of claim 14 , wherein the solvent is acetone.

Assignees

• Univ California

Inventors

• Lin Lancy
• Khine Michelle
• Park Sun-Jun

Classifications

• B32B27/06

  as the main or only constituent of a layer, {which is} next to another layer of {the same or of} a {different material (next to a layer of a particular substance B32B9/045; next to a bituminous or tarry layer B32B11/046; next to a water setting substance layer B32B13/12; next to a metal layer B32B15/08; next to a glass layer B32B17/10; next to a layer formed of natural mineral fibres or particles B32B19/045; next to a wood layer B32B21/08; next to a cellulosic plastic layer B32B23/08; next to a natural or synthetic rubber layer B32B25/08)} · CPC title

• B32B27/283

  comprising polysiloxanes · CPC title

• B32B2307/202

  Conductive · CPC title

• B32B2309/105

  Thickness · CPC title

• B32B3/28

  characterised by a layer comprising a deformed thin sheet {, i.e. the layer having its entire thickness deformed out of the plane}, e.g. corrugated, crumpled (B32B29/08 takes precedence) · CPC title