A sub-cc nonlinear piezoelectric energy harvester for powering leadless pacemakers.
A sub-cc nonlinear piezoelectric energy harvester for powering leadless pacemakers.
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DOI：
10.1177/1045389x17708344
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发表时间：
2018-03
影响因子：
2.7
通讯作者：
Karami MA
中科院分区：
文献类型：
--
作者：
Ansari MH;Karami MA
开发了一种微型非线性压电能量采集器，用于从心脏运动中为最先进的无铅心脏起搏器提供动力。能量采集器集成在无铅起搏器中，并连接到心肌。能量采集器将心肌运动转化为电能，为无铅起搏器提供动力。能量储存在电池或超级电容器中，用于起搏。该装置由约束在灰铁框架内的双压电梁组成。该系统在高温下组装，并在体温下运行。梁和框架的热膨胀系数的不匹配导致梁在体温中屈曲。这种故意的屈曲使梁不稳定，并提高了装置的发电量和稳健性。高固有频率是微电子机械系统能量采集器的主要问题。考虑到能量收集器的小尺寸，0.5cm3，自然频率预计会很高。在我们的设计中，使用弯曲的梁和验证质量显著降低了固有频率。由于梁是屈曲的，所以设计是双稳的、非线性的，可以增加输出功率。本文对该装置进行了解析建模，并对其固有频率和振型进行了解析推导。机电耦合控制方程中包含了与几何非线性相对应的项。模拟表明，该装置产生的电力足以为无铅起搏器供电。
A miniature nonlinear piezoelectric energy harvester is developed to power state of the art leadless cardiac pacemakers from cardiac motions. The energy harvester is integrated in the leadless pacemaker and is connected to the myocardium. The energy harvester converts myocardial motions to electricity to power leadless pacemakers. The energy is stored in a battery or supercapacitor and is used for pacing. The device is composed of a bimorph piezoelectric beam confined in a gray iron frame. The system is assembled at high temperature and operated at the body temperature. The mismatch in the coefficients of thermal expansion of the beam and the frame causes the beam to buckle in body temperature. This intentional buckling makes the beam unstable and improves the power production and robustness of the device. Having high natural frequency is a major problem in microelectromechanical systems energy harvesters. Considering the small size of the energy harvester, 0.5 cm3, the natural frequency is expected to be high. In our design, the natural frequency is lowered significantly using a buckled beam and a proof mass. Since the beam is buckled, the design is bistable and nonlinear, which could increase the output power. In this article, the device is analytically modeled, and the natural frequencies and mode shapes of the energy harvester are analytically derived. The terms corresponding to geometric nonlinearities are included in the electromechanical coupled governing equations. The simulations show that the device generates sufficient electricity to power leadless pacemakers.