MEMS for highly efficient interaction with a volume flow

Patent metadata

Field	Value
Publication number	US-12534359-B2
Application number	US-202218052289-A
Country	US
Kind code	B2
Filing date	Nov 3, 2022
Priority date	May 8, 2020
Publication date	Jan 27, 2026
Grant date	Jan 27, 2026

Abstract

An MEMS having a layered structure includes a cavity disposed in the layered structure and fluidically coupled to an external environment of the layered structure through at least one opening in the layered structure. The MEMS includes an interaction structure movably disposed in a first MEMS plane and in the cavity along a plane direction and configured to interact with a fluid in the cavity, wherein movement of the interaction structure is causally related to movement of the fluid through the at least one opening. The MEMS further includes an active structure disposed in a second MEMS perpendicular to the plane direction, the active structure mechanically coupled to the insulation structure and configured such that an electrical signal at an electrical contact of the active structure is causally related to a deformation of the active structure, wherein the deformation of the active structure is causally related to movement of the fluid.

First claim

The invention claimed is:

1 . A microelectromechanical systems (MEMS) with a layered structure comprising:
a cavity disposed in the layered structure and fluidically coupled to an external environment of the layered structure through at least one opening in the layered structure; an interaction structure movably disposed in a first MEMS plane and in the cavity along a plane direction and adapted to interact with a fluid in the cavity, wherein movement of the interaction structure is causally related to the movement of the fluid through the at least one opening; an active structure disposed in a second MEMS plane perpendicular to the plane direction and mechanically coupled to the interaction structure; and configured such that an electrical signal at an electrical contact of the active structure is causally related to a deformation of the active structure; wherein the deformation of the active structure is causally related to the movement of the fluid; wherein along a thickness direction of the MEMS an extension of the interaction structure is larger than an extension of the active structure.

2 . MEMS according to claim 1 , wherein the active structure comprises two actuation directions arranged opposite to each other and is adapted to perform a movement along an actuation direction in the second MEMS plane based on a first actuation signal and to perform a complementary movement opposite to the actuation direction in the second MEMS plane based on a second actuation signal.

3 . MEMS according to claim 2 , wherein the active structure comprises a first actuator for converting the first actuation signal and a second actuator for converting the second actuation signal.

4 . MEMS according to claim 2 , wherein the active structure is adapted to elongate based on the first actuation signal in a first region parallel to the actuation direction and to shorten in a second subregion; and to shorten based on the second actuation signal in the first region parallel to the actuation direction and to elongate in the second subregion.

5 . The MEMS according to claim 1 , wherein the active structure comprises a plurality of electrode elements arranged side by side and grouped into electrode pairs, main sides of adjacent electrode pairs being arranged facing each other and being connected in a central region of the electrode elements at discrete locations by inner spacer elements.

6 . The MEMS according to claim 1 , wherein the active structure comprises a plurality of electrode pairs each comprising first and second electrode elements; and adjacent electrode pairs in a central region of the electrode elements are connected at discrete locations by inner spacer elements.

7 . The MEMS according to claim 1 , wherein the active structure comprises a plurality of movable layer-assemblies mechanically connected between a MEMS substrate and a coupling element mechanically fixed to the interaction structure;
wherein each movable layer-assembly comprises a first bar, a second bar, and a third bar disposed between and electrically isolated from the first bar and second bar at discrete regions thereof, and is adapted to move along a direction of movement in the second MEMS plane in response to an electrical potential between the first bar and the third bar or in response to an electrical potential between the second bar and the third bar to move the coupling element.

8 . The MEMS according to claim 1 , wherein the active structure comprises a movable layer assembly mechanically connected between a MEMS substrate and a coupling element mechanically fixed to the interaction structure;
wherein the movable layer assembly comprises a first bar, a second bar, and a third bar disposed between the first bar and the second bar and electrically isolated therefrom at discrete regions, and is adapted to move along a direction of movement in the second MEMS plane in response to an electric potential between the first bar and the third bar or in response to an electric potential between the second bar and the third bar, to move the coupling element, wherein the discrete regions for fixing the first bar and the third bar on the one hand and the second bar and the third bar on the other hand are arranged offset from each other along an axial path of the movable layer assembly in the second MEMS plane.

9 . The MEMS according to claim 1 , wherein the interaction structure is formed electrically passively.

10 . The MEMS according to claim 1 , wherein a mechanical coupling of the interaction structure to the layer structure comprises a stiffness at most equal to a stiffness of the interaction structure.

11 . The MEMS according to claim 1 , wherein the interaction structure is elastically coupled to the layered structure by flexural spring elements.

12 . The MEMS according to claim 1 , wherein the interaction structure is arranged without suspension apart from a mechanical coupling to the active structure.

13 . The MEMS according to claim 1 , wherein a bounding structure is arranged in the first MEMS plane defining sub-cavities in the cavity, wherein fin structures of the interaction structure are movably arranged in the sub-cavities.

14 . The MEMS according to claim 1 , wherein the interaction structure comprises a plurality of plate elements arranged parallel to each other in the first MEMS plane and oriented perpendicular to the first MEMS plane and connected to a MEMS substrate in opposite edge regions.

15 . The MEMS according to claim 1 , wherein the interaction structure comprises a plurality of plate elements arranged parallel to each other in the first MEMS plane and oriented perpendicular to the first MEMS plane, the plate elements being mechanically coupled to each other in groups by means of interconnection elements into plate groups.

16 . The MEMS according to claim 1 , wherein the interaction structure is mechanically fixed to a MEMS substrate at a region remote from the active structure and is flexibly formed to deform upon deflection of the active structure.

17 . The MEMS according to claim 1 , wherein the interaction structure is coupled to the active structure by a mechanical coupling comprising a mechanical stiffness along the plane direction that is greater by a factor of at least 3 than a mechanical coupling of the interaction structure to the layered structure.

18 . The MEMS according to claim 1 , wherein a coupling element mechanically fixed the active structure to the interaction structure and adjusts a distance between the active structure and the interaction structure.

19 . The MEMS according to claim 1 , formed as a loudspeaker, microphone, ultrasonic transducer, a microdrive or micropump.

Assignees

• Fraunhofer Ges Forschung

Inventors

• Melnikov Anton
• Wall Franziska
• Monsalve Guaracao Jorge Mario
• Kaiser Bert
• Langa Sergiu

Classifications

• B81B2203/04

  Electrodes · CPC title

• B81B2203/0315

  Cavities · CPC title

• B81B2203/0136

  Comb structures · CPC title

• B81B2201/036

  Micropumps · CPC title

• B81B2201/033

  Comb drives · CPC title