Gas sensor for cantilever beam type piezoelectric actuation and piezoelectric detection

Abstract

The invention discloses a gas sensor for cantilever beam type piezoelectric actuation and piezoelectric detection. A silicon substrate is provided with a cantilever beam which takes a dielectric layer as a structural layer; the root of the cantilever beam is provided with a first piezoelectric unit and a second piezoelectric unit, wherein the first piezoelectric unit and the second piezoelectric unit are symmetrically arranged and have the same structure; the piezoelectric unit comprises a piezoelectric layer, an upper electrode and a lower electrode, wherein the upper electrode and the lowerelectrode are arranged above and below the piezoelectric layer; the lower electrode is arranged on the piezoelectric layer; the lower electrode is one part of a lower electrode metal layer and is provided with an isolated dielectric layer which covers the dielectric layer, the piezoelectric layer and the lower electrode metal layer; the upper electrode is arranged on the isolated dielectric layeron the upper part of the piezoelectric layer; the isolated dielectric layer of the cantilever beam is provided with a supermolecule compound film as a gas sensitive layer; and a lower electrode lead connected with a lower electrode and an upper electrode lead connected with the upper electrode are arranged close to the isolated dielectric layer out of the cantilever beam. In the gas sensor, the piezoelectric actuation cantilever beam resonance and a piezoelectric pickup vibration mode are adopted for detection to detect gas concentration. The sensor has the characteristics of stable performance, long service life, small volume and the like, is free from being positioned and is not impacted by the high density of gas.

Description

technical field [0001] The invention relates to a cantilever beam sensor, in particular to a cantilever beam piezoelectric drive and piezoelectric detection gas sensor suitable for detecting gas (methane) concentration in the ground environment and underground coal mines. Background technique [0002] At present, most of the sensors for detecting gas concentration use catalytic combustion combustible gas gas sensors, and optical gas gas sensors are also useful. Although these two sensors can sense information, the catalytic combustion combustible gas sensor has the problems of high working temperature, short service life and calibration cycle, and poor stability. It is easy to be poisoned under the impact of high concentration and cannot actively distinguish different flammable gases. However, the cost of the optical gas sensor is relatively high, and the power consumption is large. Contents of the invention [0003] Technical problem: The purpose of the present inventio...

AI Technical Summary

Problems solved by technology

Although these two sensors can sense information, the catalytic combustion combustible gas sensor has the problems of high working temperature, short service life and calibration cycle, and poor stability. It is easy to be poisoned under the impact of high concentration and cannot actively distinguish different combustible gases

However, the cost of optical gas sensor is higher and the power consumption is larger.

Images