Electrostatic clutch

Patent metadata

Field	Value
Publication number	US-12028679-B2
Application number	US-202217852255-A
Country	US
Kind code	B2
Filing date	Jun 28, 2022
Priority date	Jun 28, 2022
Publication date	Jul 2, 2024
Grant date	Jul 2, 2024

Abstract

Provided is an electrostatic clutch. The electrostatic clutch includes: multiple arrays of HIN electrodes, a respective pass-through channel being formed between any two arrays of the multiple arrays of HIN electrodes; and multiple arrays of biased electrodes, each array of the multiple arrays of biased electrodes moving back and forth in the respective pass-through channel such that electrostatic force is generated between the multiple arrays of biased electrodes and the multiple arrays of HIN electrodes. Such configuration allows microphone performance over a wide range of atmospheric pressures which is likely expected by applications. This is achieved electrostatically in a purely passive way having advantages over other designs which require complex electronics and active control. Physically decoupling the membrane and sense structure simplifies design of the sense structure as only small AC perturbations of the rotor is considered with no DC changes in rotor position.

First claim

What is claimed is:

1. An electrostatic clutch, comprising:
multiple arrays of grounded high impedance node (HIN) electrodes, forming one rigid movable body; and
multiple arrays of biased electrodes, forming another rigid movable body, such that an electrostatic force is generated between the multiple arrays of biased electrodes and the multiple arrays of HIN electrodes when there is a relative displacement between them; wherein
a resistive part of an HIN electrode and the capacitance formed between an HIN and neighboring biased electrodes, form a RC circuit with a cutoff frequency which determines the frequency above which the electrostatic clutch transmits a coupling force between the multiple arrays of biased electrodes and the multiple arrays of HIN electrodes and below which the electrostatic coupling force is significantly reduced or negligible.

2. The electrostatic clutch as described in claim 1 , wherein a respective pass through channel is formed between two arrays of the multiple arrays of HIN electrodes and multiple arrays of biased electrodes in a comb configuration, wherein each array of the multiple arrays of biased electrodes moves back and forth in the respective pass through channel.

3. The electrostatic clutch as described in claim 1 , wherein each array of the multiple arrays of HIN electrodes comprises a plurality of HIN electrodes and a grounded part, an insulating silicon oxide layer is provided between adjacent HIN electrodes of the plurality of HIN electrodes, and the grounded part is electrically connected to the plurality of HIN electrodes and to ground.

4. The electrostatic clutch as described in claim 3 , wherein each of the plurality of HIN electrodes comprises a first conductive polysilicon layer, a resistive bridge layer, and a second conductive polysilicon layer; the first conductive polysilicon layer is electrically connected to the second conductive polysilicon layer through the resistive bridge layer; and the grounded part is electrically connected to the second conductive polysilicon layer of each of the plurality of HIN electrodes and to ground; an insulating layer of material or air or vacuum exists between adjacent conducting polysilicon layers.

5. The electrostatic clutch as described in claim 3 , wherein each array of biased electrodes further comprises two grounded shielding electrodes, which are arranged at two ends of each array of the multiple arrays of biased electrodes.

6. The electrostatic clutch as described claim 1 , wherein within each array of biased electrodes two adjacent biased electrodes of the plurality of biased electrodes have opposite polarities and are connected by an insulating mechanical support.

7. The electrostatic clutch as described in claim 1 , wherein the multiple arrays of HIN electrodes are formed by a tuned resistance material electrically connected to a grounded polysilicon conductive material.

8. The electrostatic clutch as described in claim 1 , wherein the HIN electrodes are formed by a monolithic block of tuned resistance material without any insulating spacers; and the tuned resistance material is connected directly to a grounded conductive material without resistive bridges.

Assignees

• Aac Acoustic Tech Shenzhen Co Ltd

Inventors

• Patel Anup
• Boyd Euan James
• Kervran Yannick Pierre

Classifications

• H04N13/00

  Stereoscopic video systems; Multi-view video systems; Details thereof · CPC title

• H04R2201/003

  Mems transducers or their use · CPC title

• H04R2410/03

  Reduction of intrinsic noise in microphones · CPC title

• H04R3/04

  for correcting frequency response · CPC title

• H04R19/04 Primary

  Microphones (H04R19/01 takes precedence) · CPC title