Collaborative Research: Electrochemically driven Mechanical Energy Harvesting

能源收集是将各种形式的浪费能源转化为电力的任何技术，是现代社会能源可持续发展的关键组成部分。仅在机械能收集方面，已经证明了几种类型的发电机，包括压电式、动电式和摩擦式发电机。这些设备已经实现了广泛的应用，从小型自供电设备到可穿戴电子产品的辅助电源单元。然而，由于电流寿命短，这些发电机在相对较高的频率下收集振动能量的效率最高，而且固有地限制在人类日常活动(如步行)发生的低频区域。该研究项目旨在开发一种独特的机械能量收集器，它利用电池中电化学电池的典型配置，并专门针对收集低频运动。这样的能量收集器可以作为辅助发电机，为无处不在的计算、通信和可穿戴电子产品提供动力。该项目还将为麻省理工学院和宾夕法尼亚州立大学的本科生和研究生提供实验设计、计算材料科学和力学方面的跨学科研究经验，并加强少数人对科学和工程的参与，并激发学生对创新储能材料和能量收集研究领域的兴趣。该项目的目标是揭示电化学驱动机械能量收集的潜在机制，从而通过综合实验-建模方法控制和优化目标低频下的功率和能量产生。为了实现这一目标，该团队将采用多尺度方法对应力-电压耦合进行建模，并预测机械能量收集器的电流和功率输出。在建模结果的指导下，对机械能采集器样机进行了制造、测试和诊断。综合实验-建模方法能够从根本上了解控制机械能量收集器性能的关键设计参数，并有助于促进在理解广泛的应力介导的电化学过程方面取得变革性的进展。

Energy harvesting, which is any technology that converts otherwise wasted energy of various forms into electricity, represents a key component in energy sustainability for modern society. In mechanical energy harvesting alone, several types of electric power generators have been demonstrated, including piezoelectric, electrokinetic and triboelectric generators. These devices have enabled a wide range of applications, from small self-powered devices to auxiliary power units for wearable electronics. However, due to the short-lived electric current, these power generators are most efficient for vibrational energy harvesting at a relatively high frequency and inherently limited in the low frequency regime where every-day human activities such as walking take place. This research project aims to develop a unique type of mechanical energy harvester that exploits the typical configuration of the electrochemical cells in batteries and specifically targets harvesting low frequency motions. Such energy harvesters may work as auxiliary generators, powering ubiquitous computing, communications and wearable electronics. The project will also offer interdisciplinary research experience in experimental design, computational materials science and mechanics to both undergraduates and graduates at MIT and Penn State, as well as enhance minority involvement and participation in science and engineering, and stimulate the interests of students in the research field of innovative energy-storage materials and energy harvesting.The objective of this project is to uncover the underlying mechanisms of electrochemically driven mechanical energy harvesting so as to control and optimize power and energy generation at targeted low frequency through an integrated experimental-modeling approach. To fulfill this goal, the team will adopt a multiscale method to model the stress-voltage coupling and to predict current and power output of mechanical energy harvesters. Guided by the modeling results, mechanical energy harvester prototypes will be fabricated, tested and diagnosed. The integrated experimental-modeling approach enables a fundamental understanding of the key design parameters that govern the performance of mechanical energy harvesters in particular, and helps foster transformative progress for understanding a broad range of stress-mediated electrochemical processes in general.