Accelerometer contact microphones and methods thereof
AssigneeGeorgia Tech Research Corporation
InventorsFarrokh Ayazi, Pranav Gupta, Yaesuk Jeong
Life of this patent
Estimating the term…
Abstract
Small form-factor MEMS devices and methods of using the devices. An exemplary MEMS device includes an ACM. Certain devices comprise nanometer scale sensing gaps in the out-of-plane direction to increase vibration sensitivity in a vacuum casing. Certain devices described herein provide a differential sensing mechanism. Accelerometer contact microphones having an operational bandwidth ranging from 0 Hz and 10,000 Hz are also disclosed. The vibration acceleration sensitivity of certain devices described herein is better 100 μg√Hz.
Claims21
A device comprising:
- a suspended proof mass;
- and
- a sensing electrode separated from the suspended proof mass by a sub-micron sensing gap;
- wherein the device:
- is sensitive to vibrations from a contact source;
- is without sensitivity to air-borne acoustic emissions;
- has an operational bandwidth ranging from DC to 10 k Hz;
- is configured to sense frequencies in both:
- a range of from DC to 20 Hz resultant from tilt and/or motion;
- and
- a range of from 20 Hz to 10 k Hz resultant from vibration and/or acoustics;
- operates in vacuum of smaller than or equal to 50 Torr;
- and has out-of-plane sensitivity and micro-g resolution.
A hermetically-sealed contact microphone device comprising:
- a suspended proof mass;
- and
- a nano-gap capacitive electrode separated from the suspended proof mass;
- wherein the device;
- has out-of-plane sensitivity;
- is sensitive to vibrations from a contact source;
- is without sensitivity to air-borne acoustic emissions;
- has micro-g resolution;
- has an operational bandwidth ranging from DC to 10 k Hz;
- is configured to sense frequencies in both:
- a range of from DC to 20 Hz resultant from tilt and/or motion;
- and
- a range of from 20 Hz to 10 k Hz resultant from vibration and/or
- acoustics;
- and
- operates in a vacuum of smaller than or equal to 50 Torr.
An out-of-plane differential accelerometer comprising:
- a suspended proof mass;
- and
- a sensing electrode separated from the suspended proof mass by a nano sensing gap;
- wherein the out-of-plane differential accelerometer:
- has out-of-plane sensitivity and micro-g resolution;
- is configured to sense frequencies in both:
- a range of from DC to 20 Hz resultant from tilt and/or motion;
- and
- a range of from 20 Hz to 10 k Hz resultant from vibration and/or acoustics;
- and
- has a resonant frequency of greater than 10 k Hz.
A method comprising:
- capturing, with an out-of-plane differential accelerometer, vibrations emanating from a person;
- wherein the out-of-plane differential accelerometer comprises:
- a suspended proof mass;
- and
- a sensing electrode separated from the suspended proof mass by a nano
- sensing gap;
- and
- wherein the out-of-plane differential accelerometer:
- has out-of-plane sensitivity and micro-g resolution;
- is configured to sense frequencies in both:
- a range of from DC to 20 Hz resultant from tilt and/or motion;
- and
- a range of from 20 Hz to 10 k Hz resultant from vibration and/or acoustics;
- and
- has a resonant frequency of greater than 10 k Hz.
A method of localizing sounds in a patient comprising:
- placing two or more out-of-plane differential accelerometers upon a patient;
- capturing vibrations, with at least one of the out-of-plane differential accelerometers, emanating from the patient;
- and
- determining a source of the vibrations by calculating a vibration acceleration level at least one of the out-of-plane differential accelerometers capturing vibrations;
- wherein each out-of-plane differential accelerometer comprises:
- a suspended proof mass;
- and
- a sensing electrode separated from the suspended proof mass by a nano sensing gap;
- and
- wherein each out-of-plane differential accelerometer:
- has out-of-plane sensitivity and micro-g resolution;
- is configured to sense frequencies in both:
- a range of from DC to 20 Hz resultant from tilt and/or motion;
- and
- a range of from 20 Hz to 10 k Hz resultant from vibration and/or acoustics;
- and
- has a resonant frequency of greater than 10 k Hz.
Dependencies are inferred from the claim text.