基于微型杠杆结构谐振式差分微加速度传感器的理论建模

为了提高灵敏度和消除交叉轴串扰，提出了一种包括有效的微型杠杆结构的谐振式差分微加速度传感器，分析了该结构差分检测和消除交叉轴干扰的原理．推导了该设计的理论模型，包括结构建模和轴向力作用下谐振微梁的固有频率偏移的推导，得到了待测加速度与输出固有频率偏移的关系．使用有限元模拟来证实理论模型．模拟结果说明，该设计的灵敏度每重力加速度g高于4kHz．探讨了具体结构参数的选取与输出频差的关系，说明通过调整微型杠杆的尺寸可以进一步提高本设计的灵敏度．

Theoretical Model of a Novel Resonant Differential Microaccelerometer Based on Microleverage Structure

To enhance sensitivity and eliminate cross-sensitivity, a novel resonant differential silicon-based microaccelerometer including effective microleverage structure is designed. Differential working principle of the structure is demonstrated which shows that when it is under acceleration, the intrinsic frequency of resonant microbeam under tensile stress will increase while the intrinsic frequency of resonant microbeam under compressive stress will decrease so that differential output can be implemented. Based on certain boundary conditions, theoretical model of this design including the modeling of microleverage structure and frequency shift of resonant microbeam is proposed to obtain the relationship between applied acce leration and output frequency shift. To verify this theoretical model, finite element analysis(FEA) simulation is conducted to assert that the sensitive degree of this silicon-based design is more than 4 kHz per g. The effect of structural parameter on frequency shift of this microsensor is explored which shows that by adjusting the size of microleverage, the sensitivity can be further improved.