微型谐振气体传感器多场耦合非线性振动特性分析

Multi-field coupled nonlinear vibration analysis of micro resonant gas sensors

随着谐振子尺寸的不断减小,分子力等因素的影响越来越显著,微型谐振气体传感器的谐振子实际上处于多场耦合的工作环境中。考虑分子力、热应力和吸附气体浓度的影响,建立了谐振子的多场耦合动力学方程,利用多尺度法求出谐振子固有频率和瞬时频率,研究了谐振子固有频率随分子力、吸附气体浓度以及温度的变化规律,分析了系统参数对时域动态响应的影响。利用制造出的微型谐振气体传感器及测试系统,进行了扫频实验,得到微传感器的固有频率,与分析结果接近,验证了理论分析的正确性。研究结果对于传感器进一步微型化具有指导意义。

With the decrease of resonator size,the effects of molecular force etc.on the resonator behaviors become more obvious.The resonator of micro gas sensors usually operates in an environment of multi-field coupled interaction.In consideration of the factors of molecular force,thermal stress and density of gas,a multi-field coupled dynamic equation of the resonator was derived.Using the multi-scale method,the natural frequency and instant frequency of the sensor were obtained.The changes of the natural frequency of the sensor along with the variations of molecular force,gas density and temperature were investigated,the influences of system parameters on the time domain dynamic responses were analyzed.With a self-manufactured micro resonant gas sensor and its detecting system,the natural frequency was tested,which is in agreement with the calculated value.The correctness of the theoretical analysis was thus validated.The research results have guiding significance for the further miniaturization of such sensors.