Dielectric actuator or sensor structure and method of making it

• US 20050104145A1
• Filed: 12/17/2002
• Published: 05/19/2005
• Est. Priority Date: 12/21/2001
• Status: Active Grant

• Current Assignee: Danfoss A/S
• Original Assignee: Danfoss A/S
• Inventors: Benslimane, Mohamed Yahia, Gravesen, Peter
• Granted Patent: US 7,573,064 B2
• Time in Patent Office: Days
• US Class Current: 257/415
• CPC Class Codes: G01L 1/142 using capacitors
• CPC Class Codes: H02N 1/002 Electrostatic motors
• CPC Class Codes: H10N 30/084 by moulding or extrusion
• CPC Class Codes: H10N 30/206 using only longitudinal or thickness displacement, e.g. d33 or d31 type devices

Abstract

The present invention relates to dielectric actuators or sensors of the kind wherein electrostatic attraction between two electrodes located on an elastomeric body leads to a compression of the body in a first direction and a corresponding extension of the body in a second direction. The dielectric actuator/sensor structure comprises a first sheet of elastomeric material having at least one smooth surface and a second surface and a second sheet of elastomeric material having at least one smooth surface and a second surface. The sheets are laminated together with their second surfaces exposed, and there is provided a first electrode on the second surface of the first sheet and second electrode on the second surface of the second sheet.

Claims

1-10. -10. (canceled)

11. A dielectric actuator/sensor structure comprising:

a first sheet of elastomeric material having at least one smooth surface and a second surface;

a second sheet of elastomeric material having at least one smooth surface and a second surface;

the sheets being laminated together with their second surfaces exposed;

a first electrode being deposited on the second surface of the first sheet, and

a second electrode being deposited on the second surface of the second sheet.

12. A dielectric actuator/sensor structure as in claim 11, wherein the second surfaces are corrugated.

13. A dielectric actuator/sensor structure according to claim 11, wherein at least one of the first and second electrode consists essentially of a deposit of metal, such as silver, which has been deposited by vapor deposition or by an electrolytic process.

14. A dielectric actuator/sensor structure according to claim 11, wherein at least one of the first and second sheet of elastomeric metal consists essentially of silicone rubber.

15. A dielectric actuator/sensor structure according to claim 12, wherein the peak-to-peak amplitude of the corrugations is between 1 and 10 micrometers.

16. A dielectric actuator/sensor structure according to claim 11, wherein the electrodes have a thickness of about 20-100 nanometers.

17. A method of making a dielectric actuator/sensor structure comprising the steps of:

a) providing a generally planar mould;

b) casting a layer of elastomeric material on the mould;

c) causing the layer to have a smooth surface and a second surface;

d) curing the layer;

e) removing the layer from the mould to provide an elastomeric sheet having a smooth surface and a second surface;

f) repeating steps a) through e) to provide a second elastomeric sheet having a smooth surface and a second surface;

g) depositing at least one electrically conductive layer on the second surface of each elastomeric sheet; and

h) laminating the elastomeric sheets together with their second surfaces exposed.

18. A method according to claim 17, wherein step g) comprises depositing by vapor deposition or by an electrolytic process.

19. A method according to claim 17, wherein step h) is performed under vacuum.

20. A dielectric actuator/sensor structure comprising:

a first sheet of elastomeric material having at least one smooth surface and a second surface;

a second sheet of elastomeric material having at least one smooth surface and a second surface;

the sheets being laminated together with their second surfaces exposed;

a first electrode being deposited on the second surface of the first sheet, and

a second electrode being deposited on the second surface of the second sheet, and wherein

the first and second sheets and their respective electrodes are substantially identical.