ELECTROSTATIC ACTUATOR OF A MOBILE STRUCTURE WITH IMPROVED RELAXATION OF TRAPPED CHARGES

• US 20120223614A1
• Filed: 02/27/2012
• Published: 09/06/2012
• Est. Priority Date: 03/04/2011
• Status: Active Grant

• Current Assignee: Commissariat a L'Energie Atomique (French Alternative Energies and Atomic Energy Commission)
• Original Assignee: Commissariat a L'Energie Atomique (French Alternative Energies and Atomic Energy Commission)
• Inventors: NOWODZINSKI, Antoine
• Granted Patent: US 8,860,283 B2
• Time in Patent Office: Days
• US Class Current: 310/300
• CPC Class Codes: B81B 2201/038 Microengines and actuators not provided for in B81B2201/031 - B81B2201/037
• CPC Class Codes: B81B 3/0086 Electrical characteristics, e.g. reducing driving voltage, improving resistance to peak voltage
• CPC Class Codes: H02N 1/006 of the gap-closing type H02N1/004 takes precedence

Abstract

The device comprises a first actuating bump made from electrically conducting material with a first contact surface. A second actuating bump made from electrically conducting material is facing the first actuating bump. An electrostatic actuating circuit moves the actuating bumps with respect to one another between a first position and another position. The actuating circuit comprises a device for applying a higher potential on the second actuating bump than on the first actuating bump. A film of electrically insulating material performs electric insulation between the first and second bumps. The electrically insulating material film comprises an interface with a positive ion source and is permeable to said positive ions.

Claims

1. An electrostatic actuator comprising:

a first bump made from electrically conducting material with a first contact surface,

a second bump made from electrically conducting material with a second contact surface,

an electrostatic actuating circuit to move the first and second bumps with respect to one another, the actuating circuit comprising means for applying a potential difference between the first and second bumps,

a positive ion source devoid of water vapour,

a film of electrically insulating material permeable to said positive ions performing electric insulation between the first and second bumps and comprising an interface with the positive ion source.

2. The actuator according to claim 1, wherein the electrically insulating film comprises a blind hole and the positive ion source is situated at least in the blind hole.

3. The actuator according to claim 1, wherein the positive ion source forms at least one nodule coated in the electrically insulating film.

4. The actuator according to claim 1, wherein the positive ions are selected from hydrogen, lithium, sodium, potassium and calcium ions.

5. The actuator according to claim 1, wherein the positive ion source is formed by a porous material filled by a liquid or gaseous material releasing the positive ions.

6. The actuator according to claim 1, wherein the positive ion source comprise a solid part.

7. The actuator according to claim 1, wherein the first and second bumps are arranged in a closed cavity comprising a water vapor getter.

8. The actuator according to claim 7, wherein a covering layer covers the positive ion source.

9. The actuator according to claim 1, wherein the electrically insulating film is situated on the actuating bump subjected to the lowest potential, the other actuating bump being covered by an additional electrically insulating film.

10. The actuator according to claim 1, wherein an additional positive ion source supplies the additional electrically insulating film.