Flexible wireless passive surface acoustic wave pressure sensor with temperature self-compensation function and wide range

Abstract

The invention discloses a flexible wireless passive surface acoustic wave pressure sensor with a temperature self-compensation function and a wide range. The flexible wireless passive surface acousticwave pressure sensor comprises a lithium niobate single crystal piezoelectric film serving as a piezoelectric layer; at least one surface acoustic wave sensing unit formed on the lithium niobate single crystal piezoelectric film, wherein each surface acoustic wave sensing unit comprises a single-ended resonator formed on the lithium niobate single crystal piezoelectric film, and a microstrip antenna electrically connected with the single-ended resonator; a sealing cover covering the lithium niobate single crystal piezoelectric film, wherein the sealing cover and the lithium niobate single crystal piezoelectric film form a sealed cavity. The flexible wireless passive surface acoustic wave pressure sensor uses the lithium niobate single crystal piezoelectric film as the piezoelectric layer,so that the flexible wireless passive surface acoustic wave pressure sensor has the wide range, can detect the pressure within the range of 0 to 4 MPa, and has the temperature self-compensation function, which is conducive to improving the accuracy of the flexible wireless passive surface acoustic wave pressure sensor.

Description

technical field [0001] The invention belongs to the field of micro-nano sensors, in particular to a flexible wireless passive surface acoustic wave pressure sensor with temperature self-compensation and wide range. Background technique [0002] Surface acoustic wave (SAW) devices are an important part of MEMS, which are prepared by depositing patterned interdigital transducers on piezoelectric materials. According to the inverse piezoelectric effect, an alternating electric field applied across an interdigital transducer causes an elastic deformation of the piezoelectric material, resulting in acoustic waves propagating along the surface of the piezoelectric material. Thanks to its small size, high resonance frequency, high electromechanical coupling coefficient, high quality factor, wireless passive sensing and other advantages, surface acoustic wave devices are widely used in mobile communications, micro-nano sensors, microfluidics and other fields, especially Especially ...

AI Technical Summary

Problems solved by technology

Although traditional pressure sensors based on silicon or silicon carbide have the advantages of wide range and high temperature resistance, they have low precision and require an external power supply, which limits their application in special occasions

Although the existing surface acoustic wave pressure sensors have the advantages of miniaturization and wireless passive sensing, they are usually based on bulk piezoelectric materials (such as quartz, lithium niobate, lithium tantalate), or on hard substrates (such as Si, SOI) deposited piezoelectric film, low degree of deformation, thus limiting the range of the sensor

The reported pressure sensing range is usually lower than 2MPa, which cannot adapt to high pressure environment

If a flexible SAW device is used for pressure sensing, the range of the sensor will be increased

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