Pressure sensor with double graphite resonant beams

Abstract

The invention discloses a pressure sensor with double graphite resonant beams. The pressure sensor mainly comprises a substrate (1), an insulation layer (2), a square flat film sheet (3), a first graphite resonant working beam (2) and a second graphite resonant working beam (5). A secondary sensitive mode is adopted and the square flat film sheet is used as the primary sensitive element to convert pressure into stress on a film sheet; the graphite resonant working beams fixedly supported on two ends in the vacuum on the surface of the film sheet are used as secondary resonant sensitive elements; during work, the resonant frequency of the beams are changed along with the change of the pressure on the film sheet; and by detecting the resonant frequency of the beams, the measurement of the pressure can be achieved. According to the invention, the graphite resonant working beams in different positions have different physical field sensitive abilities to stress fields but have similar sensitive abilities to temperature fields, so quasi-differential measurement is achieved, effects caused by environmental factors like temperature are eliminated and precision and stability of the measurement are improved.

Description

technical field [0001] The invention belongs to the technical field of micro / nano electromechanical systems, and in particular relates to a double graphene resonant beam pressure sensor. Background technique [0002] Based on mechanical resonance technology, sensors realized with resonant elements as sensitive elements are called resonant sensors. The resonant sensor itself is a periodic signal output (quasi-digital signal), which can be converted into a digital signal that is easy for the microprocessor to receive with only a simple digital circuit (not A / D); at the same time, due to the repeatability and resolution of the resonant sensitive unit The force and stability are very good, so the principle of resonance measurement has naturally become the focus of people's research today. [0003] Diaphragm pressure sensors measure pressure by using the natural frequency of the diaphragm to change with the measured pressure. When the diaphragm is excited by the vibration force...

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Problems solved by technology

[0005] For resonant sensors, changes in the resonant frequency caused by environmental factors such as temperature not only affect the measurement accuracy of the sensor, but also affect the working stability of the sensor

In addition, if the pressure measurement range needs to be changed, most of the current methods have to redesign the resonant sensitive structure (hereinafter referred to as "resonant oscillator"), which also greatly increases the design cost and production cycle.

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