This paper studies the fabrication and testing of a magnet free piezoelectric energy harvester (EH) for powering biomedical devices and sensors inside the body. The design for the EH is a fan-folded structure consisting of bimorph piezoelectric beams folding on top of each other. An actual size experimental prototype is fabricated to verify the developed analytical models. The model is verified by matching the analytical results of the tip acceleration frequency response functions (FRF) and voltage FRF with the experimental results. The generated electricity is measured when the EH is excited by the heartbeat. A closed loop shaker system is utilized to reproduce the heartbeat vibrations. Achieving low fundamental natural frequency is a key factor to generate sufficient energy for pacemakers using heartbeat vibrations. It is shown that the natural frequency of the small-scale device is less than 20 Hz due to its unique fan-folded design. The experimental results show that the small-scale EH generates sufficient power for state of the art pacemakers. The 1 cm3 EH with18.4 gr tip mass generates more than16 μW of power from a normal heartbeat waveform. The robustness of the device to the heart rate is also studied by measuring the relation between the power output and the heart rate.

中文翻译：

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扇形折叠压电能量采集器为心脏起搏器供电的实验研究

本文研究了用于为体内生物医学设备和传感器供电的无磁压电能量收集器 (EH) 的制造和测试。EH 的设计是一种扇形折叠结构，由相互折叠的双压电晶片压电梁组成。制造了一个实际尺寸的实验原型来验证开发的分析模型。通过将尖端加速度频率响应函数 (FRF) 和电压 FRF 的分析结果与实验结果相匹配，对该模型进行了验证。当 EH 被心跳激发时，测量产生的电量。闭环振动器系统用于重现心跳振动。实现较低的基本固有频率是为使用心跳振动的起搏器产生足够能量的关键因素。结果表明，由于其独特的扇形折叠设计，该小型装置的固有频率小于20 Hz。实验结果表明，小规模 EH 为最先进的起搏器产生足够的功率。具有 18.4 gr 尖端质量的 1 cm3 EH 从正常的心跳波形产生超过 16 μW 的功率。还通过测量功率输出和心率之间的关系来研究设备对心率的稳健性。