MEMS transducer for interacting with a volume flow of a fluid and method for manufacturing the same

Patent metadata

Field	Value
Publication number	US-10457544-B2
Application number	US-201715843332-A
Country	US
Kind code	B2
Filing date	Dec 15, 2017
Priority date	Jun 15, 2015
Publication date	Oct 29, 2019
Grant date	Oct 29, 2019

Abstract

A MEMS transducer for interacting with a volume flow of a fluid includes a substrate including a cavity, and an electromechanical transducer connected to the substrate in the cavity and including an element deformable along a lateral movement direction, wherein a deformation of the deformable element along the lateral movement direction and the volume flow of the fluid are causally related.

First claim

The invention claimed is:

1. A MEMS transducer for interacting with a volume flow of a fluid, comprising:
a substrate comprising a cavity;
an electromechanical transducer connected to the substrate in the cavity and comprising an element deformable along a lateral movement direction, wherein a deformation of the deformable element along the lateral movement direction and the volume flow of the fluid are causally related;
wherein the deformation of the deformable element is a curvature of the deformable element in-plane with respect to the substrate.

2. The MEMS transducer according to claim 1 , wherein the electromechanical transducer is connected to the substrate in a force-fitted or in a form-fitted manner.

3. The MEMS transducer according to claim 1 , wherein the deformable element comprises an active bending bar and is configured to contact the volume flow of the fluid.

4. The MEMS transducer according to claim 1 , wherein the electromechanical transducer is configured to, in response to an electrical drive, causally cause a movement of the fluid in the cavity and/or, in response to the movement of the fluid in the cavity, to causally provide an electrical signal.

5. The MEMS transducer according to claim 1 , comprising a first and a second electromechanical transducer connected to the substrate and each comprising an element deformable along the lateral movement direction, which is configured to be deformed along the lateral movement direction, wherein the first electromechanical transducer and the second electromechanical transducer are configured to move towards each other during a first time interval and to move away from each other during a second time interval, wherein a volume of a subcavity between the first electromechanical transducer and the second electromechanical transducer is variable between the first and second time intervals.

6. The MEMS transducer according to claim 1 , comprising a multitude of electromechanical transducers connected to the substrate and each comprising an element deformable along the lateral movement direction;
wherein a first subcavity is arranged between a first electromechanical transducer and a second electromechanical transducer and a second subcavity is arranged between the second electromechanical transducer and a third electromechanical transducer.

7. The MEMS transducer according to claim 6 , wherein the first, second and third electromechanical transducers are configured to causally cause a movement of the fluid in the cavity in response to an electrical drive; and wherein the first and the second electromechanical transducer are configured to change a volume of the first subcavity with a first frequency, wherein the first and the third electromechanical transducer are configured to change a volume of the second subcavity with a second frequency.

8. The MEMS transducer according to claim 6 , wherein the first subcavity and the second subcavity comprise resonance frequencies different from each other.

9. The MEMS transducer according to claim 8 , and wherein the first and the second electromechanical transducer are configured to change a volume of the first subcavity with a first frequency, wherein the first and the third electromechanical transducer are configured to change a volume of the second subcavity with a second frequency.

10. The MEMS transducer according to claim 6 , wherein the volume flow and the deformation of the deformable element are causally related with the change of the volumes of the first subcavity and the second subcavity.

11. The MEMS transducer according to claim 6 , comprising a wall structure arranged between the first subcavity and the second subcavity and being configured to at least partially reduce a fluidic coupling between the first subcavity and the second subcavity.

12. The MEMS transducer according to claim 6 , wherein the deformable elements of the first electromechanical transducer, the second electromechanical transducer and the third electromechanical transducer comprise a bar actuator, comprising a first and a second end, respectively, wherein the bar actuator of the first electromechanical transducer is connected to the substrate at the first end and the second end, wherein the bar actuator of the second electromechanical transducer or of the third electromechanical transducer is connected to the substrate in a center region of the bar actuator.

13. The MEMS transducer according to claim 6 , wherein the substrate comprises a multitude of openings connected to a multitude of subcavities of the cavity, wherein a volume of each subcavity is affected by a deflection state of at least one element deformable along the lateral movement direction, wherein two neighboring subvolumes of subcavities may be complimentary increased or decreased in size during the first or the second time interval.

14. The MEMS transducer according to claim 6 , wherein the substrate comprises a multitude of openings connected to a multitude of subcavities of the cavity, wherein a volume of each subcavity is affected by a deflection state of at least one element deformable along the lateral movement direction, wherein values of sound pressure levels acquired based on the deformation of the deformable elements and based on the subcavities comprise a connection with a frequency of the volume flow flowing out of or into the respective subcavity, which may be represented as a function.

15. The MEMS transducer according to claim 14 , wherein the frequency of the volume flow describes a frequency-dependent course of a pressure in the fluid.

16. The MEMS transducer according to claim 1 , wherein a first subcavity adjacent to an opening of the substrate is arranged between bar structures of a first electromechanical transducer and of a second electromechanical transducer.

17. The MEMS transducer according to claim 6 , wherein the deformable elements of the first electromechanical transducer, of the second electromechanical transducer and of the third electromechanical transducer comprise a bar actuator, comprising a first and a second end each, wherein the bar actuator of the first electromechanical transducer is connected to the substrate at the first end and at the second end, wherein the bar actuator of the second electromechanical transducer or of the third electromechanical transducer is connected to the substrate in a center region of the bar actuator; and
wherein a first subcavity adjacent to an opening of the substrate is arranged between the bar structures of the first electromechanical transducer and of the second electromechanical transducer.

18. The MEMS transducer according to claim 1 , wherein a first deformable element of a first electromechanical transducer and a second deformable element of a second electromechanical transducer comprise a bar structure configured to be curved in-plane with respect to the substrate.

19. The MEMS transducer according to claim 1 , wherein the deformable element is formed to be active and is configured to interact with the volume flow, or wherein a plate element connected to the first deformable element and configured to be rigid is configured to interact with the volume flow.

20. The MEMS transducer according to claim 1 , wherein the electromechanical transducer comprises a plurality of deformable elements at least indirectly connected in an axial direction of the electromechanical transducer, which are configured to each affect a volume of a first and of a second subcavity portion.

21. The MEMS transducer accor

Assignees

• Fraunhofer Ges Forschung

Inventors

• Schenk Harald
• Conrad Holger
• Gaudet Matthieu
• Schimmanz Klaus
• Langa Sergiu
• Kaiser Bert

Classifications

• H04R23/002

  using electrothermic-effect transducer · CPC title

• H04R17/00

  Piezoelectric transducers; Electrostrictive transducers (piezoelectric or electrostrictive elements in general H10N30/00; details of piezoelectric or electrostrictive motors, generators or positioners {H10N30/00}) · CPC title

• H04R15/00

  Magnetostrictive transducers (magnetostrictive elements in general H10N30/00) · CPC title

• H04R1/08

  Mouthpieces; {Microphones;} Attachments therefor · CPC title

• H04R1/023

  Screens for loudspeakers · CPC title