驻极体微型振动能量采集器的优化设计及非线性拓调频机制研究

Exploring low-cost, easy-integrated and self-sustained energy harvesting technologies has become a key issue for the further advancement of micro energy research and Internet of things (IoT). Currently, the micro energy harvesting encounters mainly three challenges, including low output power, lack of interface circuit and poor frequency response. In order to solve these problems, the current research is focused on the electret-based vibration energy harvesters (e-VEHs) from electrical design perspective. To optimize the charge flow, a three-plate e-VEH with opposite charged electrets has been proposed. The device is fabricated with bulk silicon micromachining technologies integrated with carbon nanotube formation methods. An integrated electrical model of e-VEH has been established for the first time, incorporating mechanical vibration, energy conversion and interface circuit. This model has the potential of revealing the rules of energy generation, transfer and dissipation in e-VEH systems. Meanwhile, the feedback impact of interface circuit on the nonlinear electromechanical coupling effect as well as frequency tuning possibilities is investigated. This research could provide a basic reference for the system-level optimization of electret energy harvesting systems.

探索低成本、易集成和绿色环保的微型能量采集技术为无线传感器供电已成为微能源领域和物联网技术进一步发展亟待解决的关键问题。针对当前微型能量采集器面临的能量输出性能低、接口电路不完善和频响特性差等三个主要问题，本项目拟以基于驻极体的微型振动能量采集器为研究对象，以体微硅加工和碳纳米纤维的微纳集成制造为基础，从研究电荷流动和电路设计出发，提出一种利用相反电荷驻极体三极板结构以优化电荷产生和循环的设计方法，并建立包含机械振动、能量转化和接口电路的一体化驻极体能量采集系统整体电路模型，从而揭示机电耦合过程中的能量转化、传递和耗散规律；同时从电气系统角度，进一步探索接口电路的反向耦合对驻极体能量采集系统非线性的影响和可能的调频作用，为基于驻极体能量采集技术的整体优化提供基础的理论依据。

针对当前振动能量收集技术在频响特性、接口电路和输出性能等三方面的技术瓶颈，本研究以基于驻极体的微型振动能量采集器为研究对象，分别展开了研究并取得了以下成果：①在频响特性提升方面，本项目提出了利用非线性和多模态振动相耦合的拓频机理，首次建立了驻极体发电非线性多模振动俘能理论模型，实现了宽频带输出；②在接口电路方面，本项目首次实现了驻极体发电结构和外接电路的一体化建模，系统评估了全波整流和AC-DC转换电路的稳态性能；③在输出性能方面，提出了利用相反电荷驻极体实现性能倍增输出的设计方法，并拓展到柔性多层俘能结构，将驻极体俘能与中国传统折纸理念相结合，进一步提升了输出性能，为驻极体能量收集技术的整体优化和性能提升提供了基础的理论依据和实现方法。