Piezoelectric thin-film sensor

Patent metadata

Field	Value
Publication number	US-9970831-B2
Application number	US-201514618175-A
Country	US
Kind code	B2
Filing date	Feb 10, 2015
Priority date	Feb 10, 2014
Publication date	May 15, 2018
Grant date	May 15, 2018

Abstract

A piezoelectric sensor comprises a support structure, a channel extending through the support structure, a sensing material stack coupled to the support structure and extending over the channel, and a filler material disposed within the channel and over the sensing material stack. The sensing material stack comprises an structural layer, a first electrode layer disposed on the structural layer, a piezoelectric material disposed in a piezoelectric layer on the first electrode, and a second electrode disposed on the piezoelectric layer opposite the first electrode layer.

First claim

What is claimed is:

1. A piezoelectric sensor comprising:
a support structure;
a channel extending through the support structure;
a sensing material stack coupled to the support structure and extending over the channel, wherein the sensing material stack comprises:
a structural layer;
a first electrode layer disposed on the structural layer;
a piezoelectric material disposed in a piezoelectric layer on the first electrode layer; and
a second electrode disposed on the piezoelectric layer opposite the first electrode layer; and

a filler material disposed within the channel and over the sensing material stack.

2. The sensor of claim 1 , wherein the sensing material stack further comprises a piezoresistive layer.

3. The sensor of claim 2 , wherein the piezoresistive layer is coupled to a Wheatstone bridge circuit.

4. The sensor of claim 1 , wherein the support structure has a bulk modulus, wherein the filler material has a bulk modulus, and wherein a ratio of the bulk modulus of the support structure to the bulk modulus of the filler material is between about 10 and about 1,000,000.

5. The sensor of claim 1 , wherein the filler material comprises a shear thickening material.

6. The sensor of claim 1 , wherein a thickness of the sensing material stack is about 5 microns or less.

7. The sensor of claim 1 , wherein a thickness of the support structure is between about 0.01 millimeter to about 1.0 millimeter.

8. The sensor of claim 1 , wherein the piezoelectric material comprises lead zirconate titanate, lead magnesium niobate-lead zirconate titanate, lead zirconate niobate-lead zirconate titanate, aluminum nitride, zinc oxide, quartz, tourmaline, an Al—Sc—N ternary alloy, or any combination thereof.

9. The sensor of claim 1 , wherein the filler material comprises silicone rubber, natural rubber, a polymer, polyurethane, epoxies, adhesive resins, or any combination thereof.

10. The sensor of claim 1 , wherein the piezoelectric material comprises an oriented crystal structure.

Assignees

• Texas Instruments Inc

Inventors

• Shih Wei-Yan

Classifications

• G01P15/09

  by piezoelectric pick-up · CPC title

• G01L1/16 Primary

  using properties of piezoelectric devices · CPC title

• G01P15/123

  by piezo-resistive elements, e.g. semiconductor strain gauges · CPC title