面向无线传感网络的升频式MEMS高效能量采集机理及方法研究

Wireless sensor networks has the widespread application prospects in environments, security, transportation, health, and so on. Vibration-based MEMS energy harvesting converts the ambient vibration energy into electrical energy for powering the wireless sensor nodes. In order to improve the power output at low frequency vibrations, this project proposes an impact-based frequency-up-conversion (FUC) energy harvesting approach, which is able to convert the ambient low freqeuncy vibration into high frequency vibration of the system. The dynamics of the FUC mechanism will be studied and the model of the coupled system will be built. The dynamic, structural and surface paramters of the micro oscillation structures will be investigated. Moreover, the energy conversion relationship and efficiency of the coupled system will be analyzed. By using the micro-positioning and chip bonding techniques, the implementation of the energy harvesting system with piezoelectric thick film will be developed. The FUC mechanism would be a breakthrough for MEMS energy harvesting with high power density at low frequency vibrations. There would be a great potential development of the self-powered wireless sensor networks.

无线传感网络在环境、安全、交通、医疗健康等关系国计民生的领域具有广泛的应用前景，但电源问题是制约其发展的关键因素之一。振动微能源技术通过采集环境中振动能将其转化成电能实现为微传感器节点供电。本课题针对MEMS能量采集在低频振动环境下能量输出密度低的关键难点问题，提出基于碰撞作用的升频式高效能量采集方法，提高能量输出密度。首先研究升频机制（将低频环境振动转换为高频系统振动）的动态接触作用机理和多系统耦合振动模型，分析微结构梁的运动参数、结构参数、表面形貌等特征对振动模型的影响。在此基础上进行能量转换关系及转换效率优化研究。开展基于压电厚膜技术的MEMS高效能量采集方法研究，并结合MEMS器件键合工艺，实现升频式MEMS能量采集的系统集成封装。在低频率高密度MEMS能量采集的研究上实现突破性进展，促进其在自供电无线传感网络等相关领域的发展应用。

无线传感网络在环境监测、智能家居、医疗健康等领域具有广泛的应用前景，电源问题是制约其发展的关键因素之一。振动能量采集技术通过采集环境中振动能将其转化成电能实现为无线传感节点供电。本课题针对MEMS能量采集器在低频振动环境下能量输出密度低的关键问题，提出了基于压电厚膜技术的碰撞式升频高效能量采集方法。首先研究了将低频环境振动转换为高频系统振动的升频机制动态接触作用机理和多系统耦合振动模型，分析结构梁的结构参数、振动频率、初始间距等特征对振动模型的影响。在此基础上进行压电能量转换关系及转换效率优化研究。开展基于压电厚膜技术的MEMS高效能量采集器制备工艺研究，并结合器件键合封装工艺，实现升频式能量采集器的系统集成。本项目研究将促进低频率高密度MEMS能量采集在自供电无线传感网络等相关领域的发展应用。