Micro accelerometer based on electrostatic adsorption effect

Abstract

A micro accelerometer based on electrostatic adsorption effect. It includes: a lower base, an upper base, a movable plate, a support beam and its anchor point, a support column, a fixed drive electrode, a movable drive electrode, a fixed switch electrode, and a movable switch electrode are arranged between the lower and upper bases. The fixed drive electrodes and fixed switch electrodes are located on the inner surfaces of the lower and upper bases, and the movable drive electrodes and movable switch electrodes are located on the lower and upper surfaces of the movable plate. The invention realizes the measurement of the acceleration by measuring the closing time of the switch electrode. The present invention uses a combination structure composed of a rigid circular plate and its supporting beams as a movable structure. The contact resistance between the movable and fixed switch electrodes is relatively low, and the movable and fixed drive electrodes have relatively large electrostatic adsorption force, thereby preventing the movable switch electrodes from contacting each other. Bouncing after fixing the switching electrodes and enabling the measurement of high accelerations. The supporting beam in the invention is a non-straight beam, which can effectively eliminate the influence of thermal stress on acceleration measurement.

Description

technical field [0001] The invention relates to the field of micro-electromechanical systems, in particular to a micro-accelerometer based on electrostatic adsorption effect. Background technique [0002] Accelerometers are widely used in many fields such as industry, military, aviation, and daily life. According to the working principle, micro accelerometers can be divided into capacitive, piezoresistive, piezoelectric, vibration, switch and so on. Among them, the vibration type realizes the measurement of acceleration according to the principle that the acceleration changes the vibration frequency of the electrostatically driven beam, while the switch type drives the switch with acceleration force and makes it close when the acceleration reaches a certain threshold. These two micro-accelerometers output frequency signals and switching signals respectively and thus have the advantage of strong anti-interference performance. However, the vibration type needs to measure mul...

AI Technical Summary

Problems solved by technology

[0005] In order to solve the problems of the existing micro-accelerometers based on the electrostatic adsorption effect in the background technology, such as small electrode contact area, easy rebound of movable electrodes, and small electrostatic force, the present invention uses a rigid circular plate and a supporting beam to form a movable structure, thereby improving reliability of these microaccelerometers and makes them suitable for high acceleration measurements

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