A flexoelectric micro pressure sensor based on MEMS

Abstract

A micro electro mechanical system based flexoelectric type micro pressure sensor comprises a fixed silicon film. The top of the silicon film is embedded with a flexoelectric dielectric film and then covered with an insulating layer, an insulating layer is also arranged on the periphery of the silicon film, an upper electrode and a lower electrode are arranged on the upper surface and the lower surface of the flexoelectric dielectric film respectively, two leads for outputting measured charge signals are connected with the upper electrode and the lower electrode of the flexoelectric dielectric film respectively, and a pressure passage for exerting pressure is formed under the silicon film. The micro electro mechanical system based flexoelectric type micro pressure sensor is capable of measuring micro pressure based on positive flexoelectric effect.

Description

technical field [0001] The invention relates to the technical field of micro-electromechanical system micro-pressure sensors, in particular to a micro-electro-mechanical system-based flexoelectric micro-pressure sensor. Background technique [0002] Piezoelectric materials are widely used in micro-nano electromechanical systems. Usually, the piezoelectric effect only exists in crystals with non-centrosymmetric structures, while crystals with centrosymmetric structures do not have piezoelectric effects, which greatly limits the choice of materials. . A large number of piezoelectric materials used in industry are PZT piezoelectric ceramics. Because these materials usually contain heavy metal lead, they are harmful to the environment and human health. However, it is difficult to find more suitable materials in traditional piezoelectric materials. Piezoelectric devices generally include voltage generators, micro-drivers, sound wave generators, vibration sensors, pressure sensor...

AI Technical Summary

Problems solved by technology

In the micro pressure sensor based on thin plate theory, the strain in the film is usually linearly distributed along the thickness of the film, which makes the measurement of strain more complicated. Position close to the neutral axis of the film (strain is zero position)

In the field of structural quality detection, silicon thin film micro pressure sensors based on the linear relationship between strain and pressure have limited sensitivity, limited bandwidth, and it is difficult to access the hidden area (strain to zero position)

In addition, since the silicon thin film usually resonates with a small deflection, the deformation range of the pressure sensitive element diaphragm is small, which increases the difficulty of detection

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