Microelectronic structure with viscous damping controlled by controlling a thermo-piezoresistive effect

Patent metadata

Field	Value
Publication number	US-11414318-B2
Application number	US-201716471378-A
Country	US
Kind code	B2
Filing date	Dec 22, 2017
Priority date	Dec 22, 2016
Publication date	Aug 16, 2022
Grant date	Aug 16, 2022

Abstract

Microelectronic structure comprising at least one movable mass that is mechanically connected to a first mechanical element by a first mechanically linking connector and to a second mechanical element (24) by electrically conductive second mechanically linking connector, and a device for electrically biasing the second mechanically linking connector, the second mechanically linking connector being such that they are the seat of a thermo-piezoresistive effect, the second linking connector and the movable mass being placed with respect to each other so that a movement of the movable mass applies a mechanical stress to the second linking connector, wherein the electrically biasing device are DC voltage biasing device and form, with at least the second mechanically linking connector, a thermo-piezoresistive feedback electric circuit.

First claim

The invention claimed is:

1. A resonating microelectronic structure comprising at least one movable mass mechanically connected to at least one first mechanical element by at least a first mechanical connector and to at least one second mechanical element by at least a second electrically conductive mechanical connector, said movable mass being configured to be vibrated by an external stimulus, an electrical bias device for electrically biasing the second mechanical connector, said second mechanical connector being the object of a thermo-piezoresistive effect, the second mechanical connector and the movable mass being disposed with respect to each other such that a movement of the movable mass applies a mechanical stress to the second mechanical connector, wherein the electrical bias device is a DC voltage bias device and forms with at least the second mechanical connector a thermo-piezoresistive feedback electric circuit
wherein the first mechanical element is an anchoring pad secured to a support and the movable mass is rotatably hinged with respect to the anchoring pad and wherein the second mechanical element is a second anchoring pad secured to the support.

2. The resonating microelectronic structure according to claim 1 , wherein the thermo-piezoresistive feedback electric circuit comprises a current regulator electrically connected in series with the second mechanical connector.

3. The resonating microelectronic structure according to claim 2 , wherein the current regulator comprises at least one electrical component configured to assume a determined electrical resistance value.

4. The resonating microelectronic structure according to claim 3 , wherein the electrical component is configured to select a determined electrical resistance value from several electrical resistance values.

5. The resonating microelectronic structure according to claim 4 , wherein the electrical component is a potentiometer.

6. The resonating microelectronic structure according to claim 3 , wherein the second mechanical connector has a given electrical resistance and wherein the electrical resistance of the current regulator has a value lower than or equal to 5 times the electrical resistance value of the second mechanical connector when the movable mass is in the idle state.

7. The resonating microelectronic structure according to claim 3 , wherein the second mechanical connector has a given electrical resistance and wherein the electrical resistance of the current regulator is equal to the electrical resistance of the second mechanical connector so as to compensate for the thermo-piezoresistive effect.

8. The resonating microelectronic structure according to claim 2 , wherein the current regulator comprises at least one dipole connected in series with the second mechanical connector, said dipole having a negative resistance characteristic in the vicinity of the operating point of the resonating microelectronic structure.

9. The resonating microelectronic structure according to claim 8 , wherein the dipole is chosen from a tunnel diode, a Gunn diode, a thyristor and a feedback circuit comprising at least one operational amplifier.

10. The resonating microelectronic structure according to claim 2 , wherein the current regulator comprises at least one inductor connected in series with the second mechanical connector.

11. The resonating microelectronic structure according to claim 2 , comprising an active controller for actively controlling the bias voltage enabling a constant voltage to be applied to the second mechanical connector.

12. The resonating microelectronic structure according to claim 11 , wherein the active controller for actively controlling the bias voltage comprise a voltage feedback loop comprising measurement device for measuring the voltage at the terminals of the second mechanical connector, a comparator for comparing said measured voltage and a reference voltage, and a corrector sending a corrective signal to the electrical bias device.

13. The resonating microelectronic structure according to claim 12 , wherein the measurement device is configured to measure the voltage at the terminals of the second mechanical connector by a 4-wire method.

14. The resonating microelectronic structure according to claim 1 , wherein the second mechanical connector comprises a beam.

15. A resonating microelectronic structure comprising at least one movable mass mechanically connected to at least one first mechanical element by at least a first mechanical connector and to at least one second mechanical element by at least a second electrically conductive mechanical connector, said movable mass being configured to be vibrated by an external stimulus, an electrical bias device for electrically biasing the second mechanical connector, said second mechanical connector being the object of a thermo-piezoresistive effect, the second mechanical connector and the movable mass being disposed with respect to each other such that a movement of the movable mass applies a mechanical stress to the second mechanical connector, wherein the electrical bias device is a DC voltage bias device and forms with at least the second mechanical connector a thermo-piezoresistive feedback electric circuit,
wherein the first mechanical element is an anchoring pad secured to a support and the second mechanical element is a second anchoring pad secured to the support,
and the movable mass is rotatably hinged with respect to the anchoring pad from a pivot hinge comprising two beams extending between the anchoring pad and the movable mass.

Assignees

• Commissariat Energie Atomique
• Safran Electronics & Defense
• Commissariat A Lenergie Atomique Et Aux Energies Alternative

Inventors

• Jourdan Guillaume
• Lehee Guillaume

Classifications

• G01P1/003

  used for damping · CPC title

• B81B2201/031

  Thermal actuators · CPC title

• B81B7/02

  containing distinct electrical or optical devices of particular relevance for their function, e.g. microelectro-mechanical systems [MEMS] (B81B7/04 takes precedence) · CPC title

• B81B2203/05

  Type of movement · CPC title

• B81B2201/0271

  Resonators; ultrasonic resonators · CPC title