Elastic ribbon-like piezoelectric energy harvester for wearable devices with stretchable surfaces

This paper presents an elastic ribbon-like piezoelectric energy harvester which is targeted for skin-wearable devices by harnessing the movements of stretchable surfaces. The device aims to power up smart thin stick-on devices for healthcare monitoring. By embedding a ribbon-like PVDF film in a flexible elastomer, Ecoflex, the device is potentially able to stretch 34%, while maintaining internal strain of the film below its plastic deformation limit. Alternate electrode layout and bimorph configuration help to reduce charge cancellation, while increasing overall effectiveness. The harvester prototype with 225 mm3 active volume is able to output 15.6 V at open-circuit upon stretching 26% and is capable of generating at least 121 nJ per cycle.