Electromechanical pressure sensor

Patent metadata

Field	Value
Publication number	US-11274983-B2
Application number	US-201816625521-A
Country	US
Kind code	B2
Filing date	Jun 15, 2018
Priority date	Jul 24, 2017
Publication date	Mar 15, 2022
Grant date	Mar 15, 2022

Abstract

An electromechanical pressure sensor includes an electromechanical resonator having a driving electrode, a sensing electrode, and a beam resonator arranged between the driving and sensing electrodes. The beam resonator includes a resonator beam coupled on a first end to a first fixed anchor and coupled on a second end to a fixed second fixed anchor. The electromechanical resonator also includes a first voltage source coupled to the driving electrode and configured to provide an alternating current to the driving electrode and a second voltage source coupled to the first fixed anchor. The second voltage source provides a DC bias to the resonator beam. The electromechanical resonator further includes a third voltage source coupled to the resonator beam via the first and second fixed anchors. The third voltage source is configured to supply a voltage to the resonator beam that results in a temperature differential between the resonator beam and the first and second fixed anchors. The electromechanical resonator also includes a processor coupled to the sensing electrode and configured to correlate a voltage on the sensing electrode with a pressure value.

First claim

What is claimed is:

1. An electromechanical pressure sensor, comprising:
an electromechanical resonator, comprising a driving electrode, a sensing electrode, and a beam resonator arranged between the driving and sensing electrodes, wherein the beam resonator includes a resonator beam coupled on a first end to a first fixed anchor and coupled on a second end to a fixed second fixed anchor;
a first voltage source coupled to the driving electrode and configured to provide an alternating current to the driving electrode;
a second voltage source coupled to the first fixed anchor, wherein the second voltage source provides a DC bias to the resonator beam;
a third voltage source coupled to the resonator beam via the first and second fixed anchors, wherein the third voltage source is configured to supply a voltage to the resonator beam that results in a temperature differential between the resonator beam and the first and second fixed anchors; and
a processor coupled to the sensing electrode and configured to correlate a voltage on the sensing electrode indicative of a shift in a resonance frequency of the resonator beam with a pressure value based on the voltage supplied by the third voltage source.

2. The electromechanical pressure sensor of claim 1 , wherein the resonator beam is straight.

3. The electromechanical pressure sensor of claim 1 , wherein the resonator beam is curved.

4. The electromechanical pressure sensor of claim 1 , further comprising:
a memory coupled to the processor and storing a correlation of voltages on the sensing electrode and pressure values.

5. The electromechanical pressure sensor of claim 1 , further comprising:
an amplifier arranged between the sensing electrode and the processor.

6. The electromechanical pressure sensor of claim 1 , wherein the electromechanical resonator is a microelectromechanical resonator.

7. The electromechanical pressure sensor of claim 1 , wherein the electromechanical resonator is a nanoelectromechanical resonator.

8. The electromechanical pressure sensor of claim 1 , wherein the electromechanical resonator comprises silicon.

9. The electromechanical pressure sensor of claim 1 , further comprising:
a heater coupled to the resonator beam.

10. A method of producing an electromechanical pressure sensor, the method comprising:
providing an electromechanical resonator, comprising a driving electrode, a sensing electrode, and a beam resonator arranged between the driving and sensing electrodes, wherein the beam resonator includes a resonator beam coupled on a first end to a first fixed anchor and coupled on a second end to a fixed second fixed anchor;
coupling a first voltage source to the driving electrode, wherein the first voltage source is configured to provide an alternating current to the driving electrode;
coupling a second voltage source to the first fixed anchor, wherein the second voltage source provides a DC bias to the resonator beam;
coupling a third voltage source to the resonator beam, wherein the third voltage source is configured to supply a voltage to the resonator beam that results in a temperature differential between the resonator beam and the first and second fixed anchors; and
coupling a processor to the sensing electrode, wherein the processor is configured to correlate a voltage on the sensing electrode indicative of a shift in a resonance frequency of the resonator beam with a pressure value based on the voltage supplied by the third voltage source.

11. The method of claim 10 , wherein the resonator beam is straight.

12. The method of claim 10 , wherein the resonator beam is curved.

13. The method of claim 10 , further comprising:
coupling a memory to the processor, wherein the memory stores a correlation of voltages on the sensing electrode and pressure values.

14. A method of determining pressure, the method comprising:
applying an alternating current to a driving electrode of an electromechanical resonator, which comprises the driving electrode, a sensing electrode, and a beam resonator arranged between the driving and sensing electrodes, wherein the beam resonator includes a resonator beam coupled on a first end to a first fixed anchor and coupled on a second end to a fixed second fixed anchor;
applying a DC bias voltage to the first fixed anchor;
electrothermally heating the resonator beam with an additional voltage; and
determining the pressure by correlating a voltage on the sensing electrode indicative of a shift in a resonance frequency of the resonator beam with a pressure value based on the additional voltage.

15. The method of claim 14 , wherein the correlation of the voltage on the sensing electrode with the pressure value comprises:
selecting the pressure value from a table having a correlation between different voltages on the sensing electrode and different pressure values.

16. The method of claim 14 , wherein the electrothermal heating of the resonator beam with the additional voltage comprises: applying a DC voltage to a heater attached to the resonator beam, wherein the DC voltage is the additional voltage.

17. The method of claim 14 , wherein the electrothermal heating of the resonator beam with the additional voltage comprises: applying a DC voltage to the first and second fixed anchors, wherein the DC voltage is the additional voltage.

18. The method of claim 17 , wherein the DC voltage applied to the first and second fixed anchors is a DC voltage different from a voltage causing the middle the resonator beam to buckle at vacuum conditions.

Assignees

• Univ King Abdullah Sci & Tech

Inventors

• Hajjaj Amal
• Hafiz Md Abdullah Al
• Younis Mohammad Ibrahim

Classifications

• G01L9/0013 Primary

  of a string · CPC title

• G01L9/001 Primary

  of an element not provided for in the following subgroups of G01L9/0008 · CPC title

• G01L19/0069

  from the sensor to its support · CPC title

• G01L9/0019

  of a semiconductive element · CPC title

• G01L21/22

  using resonance effects of a vibrating body; Vacuum gauges of the Klumb type · CPC title