全纵向振动耦合的压电厚膜曲折悬臂梁能量采集方法研究

The ambient vibration energy harvesting can supply the distributed and low power sensors with the environmental-friendly and long-term electric energy. In the design of MEMS harvester, how to improve the energy density of the material at the same time reducing the resonant frequency of the structure is a hot topic. Aimed at MEMS energy harvesting, this project adopts the piezoelectric thick film and longitudinal coupling to improve the power density, combines thick film and curved cantilever without Si substrate to reduce the resonance frequency, and investigates the law of electromechanical coupling and the key MEMS technology. The contents include:（1）analysis and optimization for the electromechanical coupling characteristics of cantilever in d33 mode; (2) the principles and techniques for manufacturing the proposed cantilever, with focuses on electrodes and piezoelectric thick film manufacturing and pattern of thick film structure. This project accommodates a design principle and technological foundation for the design of high efficiency MEMS enegy harvester, and provides a technological reserve for the self-powered supplies for the low power circuits and devices.

收集环境中的振动能量可为分布式低功耗传感器提供绿色、长期的电能供给，MEMS振动能量采集技术面临的难题是如何提高材料能量密度同时降低结构的谐振频率。本项目通过采用压电厚膜和全纵向振动耦合提高材料的能量密度，探索通过无硅基压电厚膜与曲折悬臂梁设计降低谐振频率，研究相关的机电耦合规律和MEMS关键工艺。具体内容包括：（1）纵向振动耦合模式压电悬臂梁的机电耦合特性分析与优化；（2）内嵌电极的压电悬臂梁制备原理与工艺，重点研究电极与压电厚膜制备与图形化关键工艺和原理。本项目为高能效MEMS型振动俘能器设计提供一种设计原理和工艺基础，为低功耗电子电路的自供电电源提供一种技术储备。

收集环境中的振动能量可为分布式低功耗传感器提供绿色、长期的电能供给，MEMS 振动能量采集技术面临的难题是如何提高材料能量密度。本项目通过采用压电厚膜和全叉指电极纵向振动耦合来提高压电振动俘能器的能量密度，通过不锈钢基底代替硅基材料增大结构的变形和振动可靠性。建立了矩形压电悬臂梁全叉指d33模式机电耦合方程，给出了压电膜厚度、分段数、电极宽度等对输出功率的影响规律及优化方法。以3mm长、20μm厚硅基为例，电极宽度1μm, 能够输出最大功率的最有压电膜厚度是7μm，最有分段数在40~60。研究了MEMS振动俘能阵列连接方式，对一致性好的俘能器采取串并混联可不改变匹配负载大小；给出了输出电压幅度、频率和相位有差异的俘能器应采取的连接对策。以柔性不锈钢片为基底，完成了制备全叉指d33耦合压电悬臂梁的单元工艺，包括不锈钢上制作氧化硅、叉指电极制备、压电厚膜制备及表征等，采用电射流打印法制备了不锈钢基5μm厚PZT膜，有非常优异的（011）择优取向，远优于文献报导。发表期刊论文2篇，其中1篇发表在《Sensors and Actuators》，SCI/EI收录；申请发明专利2项，培养硕士研究生毕业2人，仍有3人继续从事本项目研究。