Force sensing MEMS device for sensing an oscillating force

• US 6,722,206 B2
• Filed: 05/28/2002
• Issued: 04/20/2004
• Est. Priority Date: 05/29/2001
• Status: Expired due to Fees

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Precision Engineering Center (Singapore) Pte Ltd. (Sony Group Corp.)
• Inventors: Takada, Akio
• Primary Examiner(s): Lefkowitz, Edward
• Assistant Examiner(s): ALLEN, ANDRE J
• Application Number:
  US10/160,369
• Publication Number:
  US 20020178831A1
• Time in Patent Office: 693 Days
• Field of Search: 737/79, 738/622.9, 738/623.81, 737/77, 324/252
• US Class Current: 73/779
• CPC Class Codes: H03H 2009/02496 Horizontal, i.e. parallel to the substrate plane
• CPC Class Codes: H03H 2009/02511 Vertical, i.e. perpendicular to the substrate plane
• CPC Class Codes: H03H 9/02259 Driving or detection means
• CPC Class Codes: H03H 9/2457 Clamped-free beam resonators
• CPC Class Codes: H03H 9/2463 Clamped-clamped beam resonators
• CPC Class Codes: H03H 9/462 Microelectro-mechanical filters
• CPC Class Codes: H04R 23/00 Transducers other than those covered by groups H04R9/00 - H04R21/00 diaphragms for transducers of the distributed-mode type H04R7/045

Abstract

An oscillation sensing device includes a magnetised member mounted on a substrate. A magneto-electrical material is mounted on the substrate such that the magneto-electrical material is subjected to the magnetic field generated by the magnetised member. A movable member is mounted for oscillation in response to an oscillating force. Oscillation of the movable member causes a change in the magnetic field experienced by the magneto-electrical material and an electrical property of the electro-electrical material changes in response to changes in the magnetic field experienced by the magneto-electrical material due to oscillation of the movable member.

Claims

1. A force sensing device comprises a movable member mounted for movement relative to a substrate in response to an applied force, a magnetised member mounted on the moveable member, and a magneto-electrical material mounted on the substrate such that the magneto-electrical material is subjected to the magnetic field generated by the magnetised member, movement of the moveable member causing a change in the magnetic field experienced by the magneto-electrical material, and an electrical property of the magneto-electrical material changing in response to changes in the magnetic field experienced by the magneto-electrical material due to movement of the moveable member.

2. A device according to claim 1, wherein the magneto-electrical material comprises a magneto resistive material.

3. A device according to claim 1, wherein the movable member is a micro-electro mechanical system.

4. A device according to claim 1, wherein the magnetised member and the magneto-electrical material are both in the form a thin film.

5. A device according to claim 1, wherein the movable member comprises a soft magnetic material.

6. A device according to claim 1, wherein the movable member comprises a cantilevered member.

7. A device according to claim 1, wherein the movable member comprises a linearly movable member.

8. A device according to claim 1, wherein the movable member comprises a pivotable member.

9. A device according to claim 1, wherein the movable member is adapted for oscillating movement in response to an oscillating force.

12. A frequency filter comprising a device according to claim 1, wherein the movable member has a resonating frequency.

13. A band pass filter comprising two frequency filters according to claim 12, wherein the frequency filters have different resonating frequencies and the outputs of the frequency filters are coupled together.

10. A device according to claim 10, wherein the oscillating force is an acoustic force.

11. A microphone comprising a device according to claim 10.

14. A force sensing device comprises a magnetised member mounted on a substrate, a magneto-electrical material mounted on the substrate such that the magneto-electrical material is subjected to the magnetic field generated by the magnetised member, a movable member mounted for movement in response to an applied force, movement of the moveable member causing a change in the magnetic field experienced by the magneto-electrical material, and an electrical property of the magneto-electrical material changing in response to changes in the magnetic field experienced by the magneto-electrical material due to movement of the moveable member wherein the movable member has a resonating frequency.

15. A force sensing device comprises a magnetised member mounted on a substrate, a magneto-electrical material mounted on the substrate such that the magneto-electrical material is subjected to the magnetic field generated by the magnetised member, a movable member mounted for movement in response to an applied force, movement of the moveable member causing a change in the magnetic field experienced by the magneto-electrical material, and an electrical property of the magneto-electrical material changing in response to changes in the magnetic field experienced by the magneto-electrical material due to movement of the moveable member wherein the frequency filters have different resonating frequencies and the outputs of the frequency filters are coupled together.