Multi-axis piezoelectric transducer

Patent metadata

Field	Value
Publication number	US-10263173-B2
Application number	US-201614997496-A
Country	US
Kind code	B2
Filing date	Jan 16, 2016
Priority date	Jan 16, 2015
Publication date	Apr 16, 2019
Grant date	Apr 16, 2019

Abstract

A multi-axis transducer is provided. The transducer includes: a stationary member; at least two connecting members and two or more energy-conversion elements disposed on each connecting member. Each connecting member is attached at one location thereof to one of the stationary member or a second connecting member and, in response to a stimuli, is free to move along any of three geometric axes that are perpendicular to each other. Each energy-conversion element operates to convert motion of the connecting member to electrical energy or vice versa. A common geometric plane passes through each of the at least two connecting members and the stationary member, and the two largest dimensions of each connecting member defines a geometric plane that is parallel with the common geometric plane.

First claim

What is claimed is:

1. A multi-axis transducer, comprising:
a stationary member;
at least two connecting members, each connecting member attached at one location thereof to one of the stationary member or a second connecting member and, in response to a stimuli, is free to move along any of three geometric axes that are perpendicular to each other; and
two or more energy-conversion elements disposed on each connecting member, each energy-conversion element operates to convert motion of the connecting member to electrical energy or vice versa,
wherein a common geometric plane passes through each of the at least two connecting members and the stationary member, and the two largest dimensions of one of the at least two connecting members defines a geometric plane that is parallel with the common geometric plane.

2. The multi-axis transducer of claim 1 , wherein each connecting member has a T-shaped cross-section as taken along a plane transverse to the common geometric plane.

3. The multi-axis transducer of claim 1 , wherein one or more of the connecting members have a L-shape or a U-shape structure.

4. The multi-axis transducer of claim 1 , wherein the connecting members has a unimorph structure containing at least one active layer and at least one passive layer.

5. The multi-axis transducer of claim 1 , wherein the connecting members has a bimorph structure containing at least two active layers.

6. A three-axis transducer, comprising:
a mass;
a frame defining an inner space in which the mass is disposed; and
a plurality of connecting members disposed within the inner space and arranged around the mass, wherein each connecting member
in response to stimuli, allows for linear movement of a moveable section formed of one of the mass and the frame in any of three geometric axes that are perpendicular to each other,
has a first end and a second end, the first end being attached to the mass,
is elastic,
includes a piezoelectric element having a first surface and a second surface, and
has a plurality of surface electrodes disposed on at least the first surface of each piezoelectric element,

wherein a common geometric plane passes through each of the plurality of connecting members, the frame, and the mass, and the two largest dimensions of one of the plurality of connecting members defines a geometric plane parallel to the common geometric plane.

7. The three-axis transducer of claim 6 , wherein the plurality of partitioned surface electrodes contain a first group of partitioned surface electrodes and a second group of partitioned surface electrodes,
the first group of partitioned surface electrodes completing one of harvesting electrical energy resulting from mechanical motion of the moveable section, sensing the motion of the plurality of connecting members or the moveable section by collecting charge, and applying voltage to actuate the moveable section, and
the second group of partitioned surface electrodes completing one of harvesting electrical energy resulting from mechanical motion of the moveable section, sensing the motion of the plurality of connecting members or the moveable section by collecting charge, and applying voltage to actuate the moveable section that differs from the first group of partitioned surface electrodes.

8. The three-axis transducer of claim 6 , wherein the plurality of connecting members respond to stress or strain on at least one of the plurality of the connecting members resulting from a mechanical or electrical stimuli.

9. The three-axis transducer of claim 6 , wherein the mass, the frame, and the plurality of connecting members are arranged in a monolithic device.

10. The three-axis transducer of claim 6 , wherein the plurality of connecting members are symmetrically arranged around the mass.

11. The three-axis transducer of claim 6 , further comprising:
a stationary casing, wherein
one of the mass or the frame is coupled to the stationary casing,
the one of the mass or the frame coupled to the stationary casing is fixed and forms an anchor section, and
the one of the mass or the frame not coupled to the stationary casing forms the moveable section that is free to move in any of three geometric axes that are perpendicular to each other.

12. The three-axis transducer of claim 6 , further comprising:
one or more additional structures attached or monolithically integrated on at least one of the mass and the frame, wherein at least one or more of the additional structures increases the inertial mass of the moveable section and decreases the mechanical resonance frequency of the transducer.

13. The three-axis transducer of claim 6 , further comprising:
one or more additional structures attached or monolithically integrated on the moveable section, wherein one or more of the additional structures is a sensor, an actuator, an energy reservoir, or an electronic device.

14. The three-axis transducer of claim 6 , further comprising:
a secondary moveable frame disposed within the inner space, wherein
a first set of connecting members couples the mass to the secondary moveable frame, and
a second set of connecting members couples the secondary moveable frame to the primary frame.

15. The three-axis transducer of claim 6 , wherein each connecting member is a rectangular cuboid.

16. The three-axis transducer of claim 6 , wherein each connecting member has a T-shaped cross-section as taken along a plane transverse to the common geometric plane.

17. The three-axis transducer of claim 6 , wherein each connecting member further comprises:
a second element including one of a second piezoelectric element or a non-piezoelectric element,
wherein a width of the piezoelectric element is at least twice a width of the second element.

18. The three-axis transducer of claim 6 , wherein one or more of the plurality of connecting members have a L-shape or a U-shape structure.

19. The three-axis transducer of claim 6 , wherein four surface electrodes are disposed on the first surface of the piezoelectric element.

20. The three-axis transducer of claim 6 , wherein at least one of the plurality of surface electrodes is electrically excited, wherein the at least one electrically excited surface electrode creates mechanical stress on the transducer to change the mechanical resonance frequency of the transducer.

21. The three-axis transducer of claim 6 , wherein each connecting member further comprises:
a ground electrode, wherein
the ground electrode has a first surface opposing a second surface, and
the first surface faces the second surface of the piezoelectric element.

22. The three-axis transducer of claim 21 , wherein each connecting member further comprises:
a non-piezoelectric element facing the second surface of the ground electrode.

23. The three-axis transducer of claim 21 , wherein each connecting member further comprises:
a second piezoelectric element facing the second surface of the ground electrode.

24. A three-axis piezoelectric transducer, comprising:
a platform;
a primary frame defining an inner space in which the platform is disposed;
a plurality of beams disposed within the inner space and attaching the platform to the primary frame, wherein each beam
is formed of at least one piezoelectric element,
has a plurality of partitioned surface electrodes disposed on at least one surface of the beam, wherein
the plurality of partitioned surface electrodes contain a first gr

Assignees

• Univ Michigan Regents

Inventors

• Najafi Khalil
• Aktakka Ethem

Classifications

• H02N2/188

  adapted for resonant operation · CPC title

• H01L41/0946

  Electricity · mapped topic

• H01L41/1136

  Electricity · mapped topic

• H02N2/0095 Primary

  producing combined linear and rotary motion, e.g. multi-direction positioners · CPC title

• H01L41/0825 Primary

  Electricity · mapped topic