MEMS-TYPE PRESSURE PULSE GENERATOR

• US 20120018244A1
• Filed: 07/18/2011
• Published: 01/26/2012
• Est. Priority Date: 07/22/2010
• Status: Active Grant

• Current Assignee: Commissariat a L'Energie Atomique (French Alternative Energies and Atomic Energy Commission)
• Original Assignee: Commissariat a L'Energie Atomique (French Alternative Energies and Atomic Energy Commission)
• Inventors: ROBERT, Philippe
• Granted Patent: US 8,818,007 B2
• Time in Patent Office: Days
• US Class Current: 181/142
• CPC Class Codes: B06B 1/0292 Electrostatic transducers, e.g. electret-type
• CPC Class Codes: H04R 1/005 using digitally weighted transducing elements
• CPC Class Codes: H04R 17/00 Piezoelectric transducers; Electrostrictive transducers piezoelectric or electrostrictive elements in general H10N30/00; details of piezoelectric or electrostrictive motors, generators or positioners H10N30/00
• CPC Class Codes: H04R 19/005 using semiconductor materials
• CPC Class Codes: H04R 2201/003 Mems transducers or their use
• CPC Class Codes: H04R 23/002 using electrothermic-effect transducer
• CPC Class Codes: H04R 2400/00 Loudspeakers
• CPC Class Codes: H04R 31/00 Apparatus or processes specially adapted for the manufacture of transducers or diaphragms therefor manufacture of microstructural arrangements of deformable or non-deformable structures in general B81C1/00182

Abstract

The invention relates to a device for generating or recovering acoustic energy, including:

• • at least one first deformable cavity (20) for receiving an ambient atmosphere, made in a first substrate, delimited by at least one wall including at least one mobile or deformable wall (25), and a means for making the cavity communicate with an ambient atmosphere,
  • a means (24, 24′, 24₁, 24′₁) for actuating a displacement or deformation, in the plane of the sensor, or to recover energy resulting from a displacement or deformation, in the plane of the sensor, of said mobile or deformable wall.

Claims

1. A device, of the MEMS and/or NEMS type, or of the cMUT type, for generating acoustic energy, including:

at least one first deformable cavity, made in a at least a first layer or a first substrate, extending in a plane xy, called the plane of the device, said first deformable cavity being delimited by at least one side mobile or deformable wall, and at least one opening, for transmitting at least one pressure or depression or partial vacuum pulse, produced in the first cavity, to an ambient atmosphere,

an actuator to generate a displacement or deformation, in the plane of the sensor, of said mobile or deformable wall or membrane.

2. The device according to claim 1, also including at least one secondary cavity, or buffer cavity, partially in communication with the first cavity.

3. The device according to claim 2, at least one secondary cavity being made in the plane of a second substrate, extending in a plane parallel to the plane of the device, said second substrate being different from the first substrate, or said at least one secondary cavity being made in the plane of the first substrate.

4. The device according to claim 3, said secondary cavity being made in the plane of a second substrate, extending in a plane parallel to the plane of the device, said second substrate being different from the first substrate:

the second substrate including said at least one opening;

or the second substrate being arranged on one side of the first substrate, parallel to the plane of the device, a third substrate being arranged on another side of the first substrate, parallel to the plane of the device, this third substrate including said at least one opening to transmit at least one pressure or depression or partial vacuum pulse, produced in the first cavity, to an ambient atmosphere.

5. The device according to claim 1, the actuator being of the capacitive-type or of the thermal type means, for example by bimorph or asymmetrical effect.

6. The device according to claim 5, including a capacity, provided with at least one first set of electrostatic combs, itself including a first comb, mobile in the plane of the sensor, and a second comb, stationary, the teeth of the first comb and those of the second comb alternating, and electrical contacts to apply an activation voltage to move the mobile comb relative to the stationary comb.

7. The device according to claim 1, including a first actuator, and a second actuator, arranged on either side of the first deformable cavity in the plane of the first substrate and making it possible to actuate said mobile or deformable wall in two opposite directions.

8. The device according to one of claims 1 to 7, the actuator including:

a first actuator part to create at least a first force in a first direction substantially perpendicular to said wall,

a second actuator part to create at least a second force in a second direction substantially perpendicular to the first direction,

and a converter to convert said second force into a force along said first direction.

9. The device according to claim 6, also including:

a second set of capacitive combs, the first set of capacitive combs and the second set of capacitive combs being arranged on either side of the first deformable cavity in the plane of the first substrate, and each including a comb able to move in a first direction,

and at least a third set of capacitive combs, also in the plane of the first substrate, whereof one mobile comb is able to move in a direction perpendicular to the first direction.

10. The device according to claim 1, including several first parallel deformable cavities, at least two of these cavities having shared activation means.

11. The device according to claim 1, said at least one opening, for transmitting at least one pressure or vacuum pulse, produced in the first cavity, to an ambient atmosphere, including a single opening for each deformable cavity or a membrane arranged on, or opposite, said deformable cavity.

12. The device according to claim 1, at least one mobile or deformable wall including two lateral ends, and:

being embedded or fastened at its two lateral ends,

or being rigid, and maintained at its two lateral ends by deformable elements,

or being rigid, and translatable.

13. A method for making a device, for example of the MEMS and/or NEMS or cMUT type, for generating acoustic energy, including, in the following or another order:

the production, in at least a first layer or a first substrate, extending in a plane xy, called plane of the device, of at least one first deformable cavity for receiving an ambient atmosphere, delimited by at least one mobile or deformable side wall,

the production of an actuator of said mobile or deformable side wall in the plane of the device,

the production of said at least one opening, making the first cavity communicate with an ambient atmosphere.

14. The method according to claim 13, also including the production of at least one secondary cavity, or buffer cavity, partially in communication with the first cavity.

15. The method according to the preceding claim, at least one secondary cavity being made in the plane of a second substrate, extending in a plane parallel to the plane of the device, said second substrate being different from the first substrate, or being made in the plane of the first substrate.

16. The method according to claim 15, the first substrate and the second substrate being assembled via a dielectric layer to form a SOI substrate.

17. The method according to claim 16, including an assembly of the first substrate with a third substrate, extending in a plane parallel to the plane of the device, to form said said at least one opening, to make the first cavity communicate with an ambient atmosphere.

18. The method according to claim 13, said actuator of said mobile or deformable wall being made at least partially in the first substrate.

19. A device, of the MEMS and/or NEMS type, or of the cMUT type, for generating acoustic energy, including:

at least one first deformable cavity, made in a at least a first layer or a first substrate, extending in a plane xy, called the plane of the device, said first deformable cavity being delimited by at least one side mobile or deformable wall, and a means, for transmitting at least one pressure or depression or partial vacuum pulse, produced in the first cavity, to an ambient atmosphere,

a means for actuating a displacement or deformation, in the plane of the sensor, of said mobile or deformable wall or membrane.

20. The device according to claim 19, also including at least one secondary cavity, or buffer cavity, partially in communication with the first cavity.

21. The device according to claim 20, at least one secondary cavity being made in the plane of a second substrate, extending in a plane parallel to the plane of the device, said second substrate being different from the first substrate, or said at least one secondary cavity being made in the plane of the first substrate.

22. The device according to claim 21, said secondary cavity being made in the plane of a second substrate, extending in a plane parallel to the plane of the device, said second substrate being different from the first substrate:

the second substrate including the means to make the first cavity communicate with an ambient atmosphere;

or the second substrate being arranged on one side of the first substrate, parallel to the plane of the device, a third substrate being arranged on another side of the first substrate, parallel to the plane of the device, this third substrate including the means to transmit at least one pressure or depression or partial vacuum pulse, produced in the first cavity, to an ambient atmosphere.

23. The device according to claim 19, the actuating means including capacitive-type means or thermal excitation-type means, for example by bimorph or asymmetrical effect.

24. The device according to claim 23, including a capacitive means, provided with at least one first set of electrostatic combs, itself including a first comb, mobile in the plane of the sensor, and a second comb, stationary, the teeth of the first comb and those of the second comb alternating, and means for applying an activation voltage to move the mobile comb relative to the stationary comb.

25. The device according to claim 19, including a first activation means, and a second activation means, arranged on either side of the first deformable cavity in the plane of the first substrate and making it possible to actuate said mobile or deformable wall in two opposite directions.

26. The device according to claim 19, the means for actuating a displacement or deformation of the mobile or deformable wall including:

a means for creating at least a first force in a first direction substantially perpendicular to said wall,

a means for creating at least a second force in a second direction substantially perpendicular to the first direction,

and a means for converting said second force into a force along said first direction.

27. The device according to claim 26, also including:

a second set of capacitive combs, the first set of capacitive combs and the second set of capacitive combs being arranged on either side of the first deformable cavity in the plane of the first substrate, and each including a comb able to move in a first direction,

and at least a third set of capacitive combs, also in the plane of the first substrate, whereof one mobile comb is able to move in a direction perpendicular to the first direction.

28. The device according to claim 19, at least one mobile or deformable wall including two lateral ends, and:

being embedded or fastened at its two lateral ends,

or being rigid, and maintained at its two lateral ends by deformable elements, - or being rigid, and translatable.