Flexible Piezoelectric Energy Harvesting Circuit With Printable Supercapacitor and Diodes

We report a flexible energy harvesting circuit fabricated by roll-to-roll compatible, solution-processable methods. The circuit incorporates a supercapacitor fabricated from a viscous carbon nanotube dispersion, printed Schottky diodes, and a piezoelectric element. Used low-temperature materials enabled component integration on poly(ethylene terephthalate) substrate. The supercapacitor was built with a paper separator and an aqueous NaCl electrolyte. Together with carbon-based electrodes, these materials translated into a disposable and environmentally safe electronic device. The energy harvested from mechanical movement was used to drive a commercial electrochromic display.