MEMS压电-磁电复合式振动驱动微能源的设计∗

摘要

在单一效应的MEMS振动驱动微能源的基础上,提出了一种MEMS压电-磁电复合振动驱动微能源器件。该微能源由八悬臂梁-中心质量块结构和永磁铁两部分组成,环境振动使中心质量块振动,PZT压电敏感单元由于压电效应产生电势差；同时中心质量块上集成的高密度线圈切割磁感线产生感应电动势,将压电转换与磁电转换相结合把振动能转换为电能。建立了该结构的数学模型并用有限分析软件Ansys12.0对该器件进行力学特性分析,最后对加工出的微能源进行性能测试。测试结果表明,该微能源谐振频率为8 Hz,易与环境发生共振；在共振条件下,施加1 gn 的加速度,器件压电发电开路输出电压峰峰值达154 mV,磁电发电开路输出电压峰-峰值达8 mV,有望为无线传感网络节点提供稳定的能源。%A MEMS piezoelectric and electromagnetic hybrid vibrational micro-power harvesting devices was proposed based on the single effect of MEMS micro-power. The sensor consists of eight cantilever beams-center quality block structure and permanent magnet. Though the environment vibration,PZT piezoelectric units produce voltage by external force due to piezoelectric effect;at the same time,high-density coil which is integrated on center mass, cutting line magnetic induction voltage is induced. We can integrate the two energy conversions of piezoelectric and electromagnetic power generation which improves the overall output voltage of device. The calibra-tion method and finite element method for the accelerometer was proposed. Finally,the experimental results were presented. The experimental results show that the resonant frequency of the micro-power device is 8Hz, which is easy to reach to environmental vibration resonance. Open circuit output peak-peak voltage of the piezoelectric part is 154 mV and open circuit output peak-peak voltage of the electromagnetic part is 8 mV under the acceleration of 1 gn and freguency of 8 Hz. And it is expected to sloving the power supply problem of wireless sensor network nodes.