Composite structure for a pressure sensor and pressure sensor
A composite structure for a pressure sensor, a pressure sensor, a method of pressure sensing using the pressure sensor, and a method of fabricating a composite structure for a pressure sensor. The method of fabricating a composite structure for a pressure sensor comprises the steps of forming an array of microstructures made from an elastomeric material; and forming a flexible conductive coating on the array of microstructures such that a surface morphology of microstructures is substantially maintained for the coated array of the microstructures; wherein the conductive coating exhibits a Young's modulus that is higher than that of the elastomeric material.
1. A composite structure for a pressure sensor, the composite structure comprising:
an array of microstructures made from an elastomeric material; and
a flexible conductive coating formed on the array of microstructures such that a surface morphology of the array of microstructures is substantially the same as for the coated array of the microstructures;
wherein the flexible conductive coating exhibits a Young's modulus that is higher than that of the elastomeric material;
wherein the flexible conductive coating comprises a low dimensional electronically active material formed on an intermediate uniform layer between the array of microstructures and the low dimensional electronically active material; and
the composite structure further comprising electrodes disposed on the coated array of microstructures and configured for measuring a change in contact resistance between the low dimensional electronically active material and the electrodes as a result of pressure on the composite structure.
2. The composite structure of claim 1 , wherein the Young's modulus of the conductive coating is about one order of magnitude higher than that of the elastomeric material, or more.
3. The composite structure of claim 1 , wherein the flexible conductive coating comprises an electronically active material exhibiting electron tunneling properties.
4. The composite structure of claim 3 , wherein the electronically active material comprises a uniform layer or nanoflakes.
5. The composite structure of claim 1 , further comprising a substrate for the array of microstructures.
6. A pressure sensor comprising the composite structure of claim 1 .
7. The pressure sensor of claim 6 , exhibiting a reduced hysteresis based on elastic properties of the composite structure compared to viscoelastic properties of the elastomeric material of the array of microstructures.
8. The pressure sensor of claim 6 , exhibiting a substantially frequency independent output as a function of applied pressure.
9. The pressure sensor of claim 6 , exhibiting a substantially temperature independent output as a function of applied pressure.
10. The pressure sensor of claim 6 , exhibiting a substantially humidity independent output as a function of applied pressure.
11. The pressure sensor of claim 6 , wherein the electrodes are disposed on an opposite side of the flexible conductive coating compared to the array of microstructures.
12. The pressure sensor of claim 11 , wherein the flexible conductive coating comprises an electronically active material exhibiting electron tunneling properties.
13. The pressure sensor of claim 11 , wherein the electrodes comprise two interdigital electrodes.
14. A method of pressure sensing using the pressure sensor of claim 6 .
15. A method of fabricating a composite structure for a pressure sensor, the method comprising the steps of:
forming an array of microstructures made from an elastomeric material; and
forming a flexible conductive coating on the array of microstructures such that a surface morphology of microstructures is substantially the same as the coated array of the microstructures;
wherein the flexible conductive coating exhibits a Young's modulus that is higher than that of the elastomeric material; and
wherein forming the flexible conductive coating comprises forming an intermediate uniform layer on the array of microstructures and providing a low dimensional electronically active material on the intermediate uniform layer;
the method further comprising disposing electrodes on the coated array of microstructures and configured for measuring a change in contact resistance between the low dimensional electronically active material and the electrodes as a result of pressure on the composite structure.
16. The method of claim 15 , wherein forming the flexible coating comprises drop casting the low dimensional electronically active material onto the intermediate uniform layer.
17. The method of claim 16 , comprising blading the intermediate uniform layer onto the array of microstructures prior to drop casting the low dimensional electronically active material.
18. The method of claim 15 , wherein the flexible conductive coating comprises an electronically active material exhibiting electron tunneling properties.
19. The method of claim 18 , wherein the electronically active material comprises a uniform layer or nanoflakes.
20. The method of claim 15 , further comprising disposing electrodes on an opposite side of the flexible conductive coating compared to the array of microstructures.