Electrochemically-Driven Mechanical Energy Harvesting

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.