Micro scale mechanical rate sensors

• US 8,479,574 B2
• Filed: 08/31/2010
• Issued: 07/09/2013
• Est. Priority Date: 03/03/2008
• Status: Expired due to Fees

• Current Assignee: Ramot at Tel Aviv University Limited (Tel Aviv University)
• Original Assignee: Ramot at Tel Aviv University Limited (Tel Aviv University)
• Inventors: Schreiber, David, Krylov, Viacheslav, Shacham-Diamand, Yosi
• Primary Examiner(s): KWOK, HELEN C
• Application Number:
  US12/871,912
• Publication Number:
  US 20110048130A1
• Time in Patent Office: 1,043 Days
• Field of Search: 735/041.3, 735/041.2, 735/040.4, 735/040.2, 735/041.4, 735/041.5, 735/041.1, 735/040.8
• US Class Current: 73/504.12
• CPC Class Codes: G01C 19/56 Turn-sensitive devices using vibrating masses, e.g. vibratory angular rate sensors based on Coriolis forces
• CPC Class Codes: Y10T 29/49826 Assembling or joining

Abstract

An angular rate sensor device is presented. The sensor device comprises a disk-shaped structure having a proof mass region and a flexible portion. The disk-like structure is coupled to a substrate in a manner enabling a wave type precession motion such that during the wave type precession motion each material point of the proof mass performs elliptic motion.

Claims

1. An angular rate sensor for determination of an angular rate of rotation of a rotatable substrate aggregated with the angular rate sensor, the sensor having a disk-shaped structure comprising:

a central stand region attached to the rotatable substrate at one end and extending from the rotatable substrate in a direction substantially perpendicular to an axis of rotation of the rotatable substrate;

an annular plate region surrounding the central stand region and being attached to another end of the central stand region such that a plane of the annular plate region is substantially parallel to the axis of rotation of the rotatable substrate; and

a periphery region surrounding the annular region and extending from the annular plate region outwards from the annular plate region in a periphery region plane being substantially parallel to the axis of rotation of the rotatable substrate.

2. The angular rate sensor of claim 1, wherein said annular plate region is a relatively flexible annular region, whereas said periphery region is a relatively rigid region as compared to the annular plate region.

3. The angular rate sensor of claim 2, wherein said relatively flexible annular region is configured to be deformable along a circumference thereof and along axes perpendicular to the axis of rotation.

4. The angular rate sensor of claim 2, wherein the flexible annular region is configured as a region of an appropriate thickness allowing the deformation and having a certain moment of inertia with respect to an axis of symmetry of the disk-shaped structure.

5. The angular rate sensor of claim 4, wherein said periphery region is much thicker than the annular plate region.

6. The angular rate sensor of claim 1 attached to the rotatable substrate by a flexible stand having a bending and torsion compliances.

7. The angular rate sensor of claim 1, fabricated by micro-machining.

8. The angular rate sensor of claim 6, fabricated in a silicon-on-insulator (SOI) wafer.

9. A method of manufacturing an angular rate sensor for determination of an angular rate of rotation of a rotatable substrate aggregated with the angular rate sensor, the method comprising:

patterning a disk-shaped structure to define (i) a central stand region configured for attaching to the rotatable substrate at one end of the central stand region;

(ii) an annular plate region surrounding the central stand region and being substantially perpendicular to the central stand region; and

(iii) a periphery region surrounding the annular region and extending therefrom outwards in the same plane as the annular plate region; and

attaching the central stand region to the rotatable substrate such that the central stand region extends from the rotatable substrate in a direction substantially perpendicular to an axis of rotation of the rotatable substrate.

10. A method for determination of an angular rate of rotation of a rotatable substrate aggregated with the angular rate sensor, the method comprising:

(a) attaching an angular rate sensor to the rotatable substrate, said angular rate sensor having a disk-shaped structure comprising;

a central stand region configured for attaching to the rotatable substrate at one end and extending from the rotatable substrate in a direction perpendicular to an axis of rotation of the rotatable substrate;

an annular plate region surrounding the central stand region and being attached to another end of the central stand region such that a plane of the annular plate region is parallel to the axis of rotation of the rotatable substrate; and

a periphery region surrounding the annular region and extending from the annular plate region outwards in a periphery region plane being substantially parallel to the axis of rotation of the rotatable substrate;

(b) exciting the disk-shaped structure rotated together with the rotatable substrate to cause a precession motion of the periphery region with tilting of at least the periphery region plane relative to the axis of rotation of the rotatable substrate;

(c) measuring a change of the precession motion and determining a precession phase indicative of the angular rate of the disk-shaped structure rotation.