面向无线传感器网络的压电-摩擦复合式MEMS宽频能量采集器研究

With the development of the wireless sensor network (WSN) technology, wireless sensor node numbers are obviously increasing, and they are applying for the application of the harsh environment. The energy supply becomes the urgent question for the development of wireless sensor network. Energy harvesting technology would be an alternative method to solve the problem of wireless sensor node power supply, which converts vibration energy from the ambient into electricity . Currently, the low output power and narrow working frequency band are the key problem of the micro energy harvester, which should be solved for the further application. This project proposes an integrated piezoelectric and triboelectric hybrid energy harvester with a two degree-of-freedom body to improve the conversion efficiency. Compared to the traditional single mechanism energy energy, this hybrid mechanisms harvester can increase further the output power. The impact-type coupling structure with two vibration modes can broaden the frequency range of the device and realize the wide-band vibration energy collection and conversion. A energy harvester prototype is fabricated by MEMS key technology, such as high performance piezoelectric thick film, micro-nano structure of triboelectric surface. The experiments are conducted to evaluate and analysis the output performance and verify the feasibility, and effectiveness of the above principle. This project is an attempt to broaden the band of the piezoelectric-triboelectric hybrid micro energy harvester It is expected to overcome the disadvantages of recently developed devices such as a narrow frequency band and low output performance. This project focuses the technical and application development for the application of WSN.

随着无线传感器网络（WSN）技术的发展，WSN节点数目越来越庞大，且通常面临无人无源应用场景，因此能量供给问题是制约WSN快速发展的主要瓶颈之一。将环境振动能转化为电能的能量采集技术是解决WSN节点供能问题的一种有效方式。目前输出性能低、工作频带窄已成为微型能量采集器研究亟需解决的关键问题。本项目提出一种集成压电和摩擦两种换能机制的复合式能量采集器，解决传统单一机制换能效率低、输出功率小的问题；利用两自由度和碰撞式非线性相结合的方式拓宽频带，突破单一拓宽方法的局限；通过开发高性能压电厚膜和金属质量块摩擦微结构关键工艺，制作MEMS能量采集器实验样机，对其输出性能进行评估和分析，并验证上述原理的可行性和有效性，为实际应用于WSN节点奠定技术和应用基础。

无线传感器网络技术（WSN）快速发展的主要瓶颈之一是能源受限问题。通过采集传感器节点所处环境无处不在的振动能转换为电能是解决WSN节点长期供电问题的主流方案之一。然而，能量转换效率低、工作频带窄是制约该项技术推广应用的主要因素。本项目设计了一种新型压电-摩擦复合宽频能量采集器，采用压电和摩擦电两种技术同时进行振动能的高效采集，并在结构上利用两自由度和碰撞相结合的工作机制有效拓宽工作频带。. 项目系统地研究了压电和摩擦电能量转换单元，从结构设计、理论建模、有限元仿真分析、加工工艺和动态测试实验等五个方面开展。设计了单自由度/两自由度压电和摩擦能量采集器等多种样机；研究了两自由度压电振动能量采集器的机电耦合模型，并对摩擦电转换单元进行了理论分析；建立了压电转换单元的有限元模型，进行了主结构的参数优化；提出了一种磷青铜作为基底，基于键合与减薄技术的高性能压电厚膜制备方法，并在此基础上开展了MEMS加工工艺研究，制作了多种样机；进行了性能测试研究，压电-摩擦电复合能量采集器压电转换单元的工作频宽为23Hz，最大输出功率达0.271mW，而摩擦转换单元工作频宽为31Hz，最大输出功率达34.07μW；设计了电源管理电路，并开展了为低功耗设备和无线传感器网络节点供电应用初步实验研究，证明了实际应用的可行性。. 所研制器件可有效采集低频且频率多变通常环境中的振动机械能，有望为无线传感器网络节点等电子器件提供持久的、无需人工维护的电能，实现自供能无线传感器网络提供了可能性，具有一定的学术价值。