MEMS fluid viscosity sensor chip based on in-plane resonance and preparation method thereof

Abstract

The invention discloses a MEMS fluid viscosity sensor chip based on in-plane resonance and a preparation method thereof. The chip comprises a silicon substrate, four elastic fixed support beams and an intermediate vibrator. Two leads are respectively arranged on the fixed support beams in two sides of the vibrator. A magnet at the bottom of the chip is used for providing a constant magnetic field. The direction of the magnetic induction line is perpendicular to the chip plane. Each one of the leads is applied with sinusoidal alternating currents having a certain frequency and the lead carries out in-plane vibration under action of an alternating Lorentz force on the fixed support beams so that the vibrator and the fixed support beams in the other side are driven to produce forced vibration and the other lead cuts the magnetic induction line and produces the induced electromotive force. The H-type silicon micro-double-end fixed support beam structure is immersed in the fluid to be detected and the frequency of the sinusoidal alternating current is changed so that fixed support beam resonance is produced. According to the amplitude of the output of the induced electromotive force, resonance frequency of the fixed support beams in the detected fluid is acquired. Through change of the fixed support beam resonant frequencies in different fluids, fluid viscosity can be measured.

Description

technical field [0001] The present invention relates to the field of MEMS (Micro Electromechanical Systems, micro-mechanical electronic systems) sensors, more specifically, to a MEMS fluid viscosity sensor chip based on in-plane resonance and a preparation method thereof. Background technique [0002] MEMS viscosity resonance sensor is based on the principle of resonance to detect the viscosity parameters of fluids. It has the characteristics of miniaturization, integration and multi-function of MEMS sensors, and has broad application prospects in aerospace, oil exploration, biomedicine and other fields. However, the current MEMS viscosity resonance sensor is still insufficient. When measuring viscous fluids, the greater the viscosity of the fluid, the greater the damping force on the resonator in the sensor chip, the quality factor of the viscosity sensor is significantly reduced, and the measurement accuracy of the sensor is reduced. The sensitivity and sensitivity limit t...

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Problems solved by technology

[0004] The purpose of the present invention is to provide a MEMS fluid viscosity sensor chip based on in-plane resonance and its preparation method, by realizing the in-plane vibration of the H-shaped silicon micro-double-end fixed beam structure, the pressure film damping between the fluid and the fluid is replaced by The synovial film damping can significantly reduce the damping force of the viscosity sensor chip in the fluid environment, and improve the measurement accuracy, sensitivity and stability of the viscosity sensor to the fluid viscosity; to effectively solve the large fluid damping of the MEMS viscosity sensor in the prior art , The working problem of low measurement accuracy for high-viscosity fluids

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