This article presents the design and testing of a novel two-directional (2-D) piezoelectric stack-based energy harvester for capturing the mechanical energy from the human footstep. The uniqueness of the harvester lies in the fact that the energy of 2-D excitation is scavenged by a single piezoelectric stack transducer, which can reduce the loss of harvestable energy. The harvester is constructed by the integration of permanent magnets, position protection plates, and multistage force amplification frame. The input force and input displacement are restricted to guarantee the device’s safety. The reported multistage force amplification frame with leverage mechanism and bridge-type amplifier enlarges the force acting on the piezoelectric stack, which further improves the power output. A linear guiding mechanism based on leaf flexure is applied to minimize the impact of input forces in other than moving directions. Through analytical modeling, the main architectural parameters of the device are determined. Simulation study with finite-element analysis is conducted to optimize the device parameters for achieving the largest force amplification ratio with a high safety factor. A prototype harvester is fabricated for experimental study. Results demonstrate the feasibility of the developed 2-D piezoelectric stack-based energy harvester.

中文翻译：

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具有永磁体和多级力放大器的新型双向压电能量采集器的设计。

本文介绍了一种新型的基于双向（2-D）压电堆栈的能量收集器的设计和测试，该能量收集器用于从人的脚步中捕获机械能。收割机的独特之处在于，一个压电堆栈换能器可以清除二维激励能量，从而减少可收割能量的损失。收割机由永磁体，位置保护板和多级力放大框架组成。输入力和输入位移受到限制，以确保设备的安全性。所报道的具有杠杆机构和桥式放大器的多级力放大框架增大了作用在压电叠层上的力，从而进一步提高了功率输出。应用了基于叶片挠曲的线性导向机制，以最大程度地减小输入力在移动方向以外的影响。通过分析建模，可以确定设备的主要架构参数。进行了有限元分析的仿真研究，以优化设备参数，以实现具有最大安全系数的最大力放大率。制造了原型收割机用于实验研究。结果证明了开发的二维压电堆式能量收集器的可行性。进行了有限元分析的仿真研究，以优化设备参数，以实现具有最大安全系数的最大力放大率。制造了原型收割机用于实验研究。结果证明了开发的基于二维压电堆的能量收集器的可行性。进行了有限元分析的仿真研究，以优化设备参数，以实现具有最大安全系数的最大力放大率。制造了原型收割机用于实验研究。结果证明了开发的二维压电堆式能量收集器的可行性。