用于微量气体检测的同步共振悬臂梁结构感应机理研究及其性能优化

The resonant sensor for gas detection based on the micro-cantilever has the advantage of high response speed, easy integration and so on. But it can not achieve high resolution detection of some kinds of trace gas. The forward research shows that the application of synchronized oscillation with nonlinear vibration mechanics can achieve the effect of multiplication in frequency, with excitation in low frequency and picking up in high frequency, which has the advantage of enhancing the resolution of micro-cantilever remarkably. This project faces the urgent need of trace gas detection, studying the high-resolution sensing mechanism based on synchronized oscillation; designs a resonant sensor based on multiplication of frequency with synchronized oscillation, assisted by piezoelectric segmentation for vibration picking up. Building a new approach to achieve trace gas detection with the division of excitation & picking up, and the multiplication of output voltage, implementing the improvement of resolution and detection sensitivity; proposes the analyzing method with variable position excitation, studying synchronized oscillation energy conversion mechanism, disclosing inhibition mechanism of energy loss, to further improve the resolution of the sensor; proposes nonlinear analyzing method of variable coupling structure, which means that changing the coupling coefficient and nonlinear coefficient affects the range of frequency of the synchronized region, creating a theory that the regional variation with nonlinear coupling synchronized oscillation. The launch of this project is aim to achieve the innovation in theory and structure related to high-resolution gas sensor, which has great significance to promote the development of trace gas sensor.

基于微悬臂梁的谐振式气体传感器具有响应速度快、易集成等优点，但无法实现某些微量气体的高分辨率检测。预研结果表明应用非线性振动力学的同步共振原理，可实现低频激振高频拾振的频率倍增效应，大幅提高微悬臂梁结构的分辨率。本项目面向微量气体检测的迫切需求，研究基于同步共振的高分辨率感应机理。提出基于同步共振频率倍增原理、辅助以压电分割拾振结构的谐振式传感器，构建可实现激振与拾振分离、输出电压倍增的微量气体检测新方法，提高分辨率、检测灵敏度；提出变位置激励分析法，研究同步共振能量传递转化机制，揭示能量损耗的抑制机理，进一步提高传感器的分辨率；提出变耦合结构非线性分析法，即通过调整耦合系数及非线性系数影响同步共振区域的频率范围，探究非线性耦合同步共振区域变化理论。本项目的开展有利于推动高分辨率气体传感器原理及结构创新，对促进微量气体传感器发展具有重要意义。

基于悬臂梁结构的谐振式气体传感器具有响应速度快、易集成等优点，但无法实现微量气体的高分辨率检测。利用非线性振动力学的倍频共振原理，可实现低频激振高频拾振的频率倍增效应，大幅提高悬臂梁结构的传感分辨率。本项目面向微量气体检测的迫切需求，研究构建了基于同步共振的高分辨率感应机理。提出并研究了一种基于倍频共振的高灵敏度传感机理，设计了一种可实现高分辨率检测的Π型耦合悬臂梁结构，并辅助压电分割拾振设计实现了质量扰动的高灵敏度检测。研究了Π型耦合悬臂梁结构的倍频共振区域，以及支撑损耗和热弹性损耗的抑制机理。搭建了基于力-电耦合原理的激振拾振测试与实验平台，实现了倍频共振结构的自激励和自检测。优化了Π型耦合悬臂梁结构的防扭转性能和倍频共振性能。采用附加质量等效替代微量气体，开展了质量扰动的高分辨率、高灵敏度传感实验研究，以及不同交变电压下倍频共振区域变化实验研究，验证了倍频共振结构用于微量气体检测的可行性。本项目的开展有利于推动高分辨率气体传感器原理及结构创新，对促进微量气体传感器发展具有重要意义。