High-sensitivity MEMS resonant acceleration sensor

Abstract

The invention provides a high-sensitivity MEMS resonant acceleration sensor. The sensor comprises a sensitive mass block (1) provided with a first hollow area (11); a supporting structure (2) used forsupporting the sensitive mass block (1); and a sensitization structure (3) located in the first hollow area (11) and forming a parallel plate capacitor bank with the sensitive mass block (1). The sensitive mass block (1) and the supporting structure (2) are equivalent to a 'mass-spring-damping 'system, and sensibilization bias voltage is applied to the two ends of the parallel plate capacitor bank, so that the parallel plate capacitor bank generates an electrostatic negative stiffness effect to reduce the effective stiffness of the 'mass-spring-damping' system. When acceleration is input, thesoftening effect of the electrostatic negative stiffness reduces the effective stiffness of the mass-spring-damping system, so that the conduction efficiency of converting inertia force into resonator sensitive axial force is improved, and finally, the sensitivity of the sensor is effectively improved.

Description

technical field [0001] The present disclosure relates to the technical field of sensors, in particular to a high-sensitivity MEMS resonant acceleration sensor. Background technique [0002] Micro-Electro-Mechanical System (MEMS) acceleration sensors can be divided into piezoresistive, piezoelectric, tunneling, capacitive, and resonant based on the sensitivity principle. The MEMS resonant acceleration sensor obtains the acceleration by detecting the change of the natural frequency of the resonant structure. [0003] In related technologies, the working principle of the common MEMS resonant acceleration sensor is: the external acceleration acts on the sensitive mass, and the inertial force generated in the direction of the sensitive axis is amplified by the lever and transmitted to the resonator, so that the sensitivity of the resonator The axial stress changes, which causes the resonant frequency of the resonator to change. By detecting the frequency change of the resonator,...

AI Technical Summary

Problems solved by technology

Sensitivity is one of the key indicators of sensor performance. In order to further improve the sensitivity, a multi-level lever amplification structure can be used, but limited by the amplification efficiency and mechanical complexity of the multi-level lever structure, the sensitivity improvement by this method is also limited. ; By optimizing the support structure to make its mechanical stiffness smaller in the direction of the acceleration sensitive axis, the sensitivity can also be improved, but it is limited by the robustness of the sensor and the processing technology

In addition, by adopting a novel mechanical structure design or optimizing and improving the mechanical structure design to increase sensitivity, the sensing element cannot be adjusted dynamically after processing, which limits the versatility and flexibility of the sensor.

Images