ELECTROCHEMICAL NANOGENERATORS FOR WEARABLE ENERGY HARVESTING
The advent of the lithium ion battery enabled a revolution in wireless electronic devices. The next wave of wireless devices, from smart watches to biosensors, are smaller, and often embedded within existing infrastructures like clothing. As these small devices become more numerous, recharging each one becomes cumbersome, which has led researchers to explore point of use ambient energy harvesters. This study investigates the properties of electrochemical generators, a mechanical energy harvesting system based on the stress induced ion flow in insertion electrodes. The electrochemical generator is assembled using Prussian Blue as the host material. The influence of ion size, bending radius, and temperature are experimentally tested to better understand the underlying mechanism leading to current generation. These mechanistic insights are leveraged to create a wearable energy harvester with power generation up to 3.8 μW/cm^2 at frequencies characteristic of human motion. The harvester is then constructed in the form of a fiber and incorporated in textiles, demonstrating the energy harvesting and motion sensing capabilities of this platform.