Continuous Energy Harvesting and Motion Sensing from Flexible Electrochemical Nanogenerators: Toward Smart and Multifunctional Textiles.

Here, we demonstrate the utilization of biocompatible Prussian blue (PB) active coatings onto polyester-carbon nanotube (CNT) threads to enable a fiber-based platform for both power harvesting and continuous motion sensing. First, we show experimental evidence supporting that the mechanistic power generating mechanical-electrochemical coupling in an electrochemical generator (ECG) is best achieved with K-ion insertion, in contrast to the expected preference for Li-ion insertion for batteries. We then construct KPB fibers and demonstrate power generation in an ECG device up to 3.8 μW/cm at low frequencies relevant to human motion in either an aqueous or polymer gel electrolyte media. Further, by stitching these yarns into gloves or arm sleeves, our results show the continuous monitoring of finger or arm motion, respectively, during slow and repetitive human motion. Overall, our work demonstrates an ECG platform that overcomes the performance and integration barriers toward combined textile integration and human motion sensing while leveraging common materials and understanding extending from alkali metal-ion batteries.