Origin of enhanced piezoelectric energy harvesting in all-polymer-based core-shell nanofibers with controlled shell-thickness

Polymer nanofiber-based piezoelectric composites have been actively investigated as ideal energy generators for low-power-consuming electronic devices. Herein, we introduce a core-shell nanofiber-based piezoelectric energy harvester consisting of poly (vinylidene fluoride-trifluoroethylene (P(VDF-TrFE)) as a piezoelectric shell and poly (3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) as a conductive core, which was optimized primarily by adjusting the relative shell thickness. The thinnest shell layer exhibited the best output performance, i.e.,-8.76 V and-547 nA, which correspond to the 10-fold and 5-fold increases relative to the reference values for only P(VDF-TrFE) nanofibers. Almost doubled performance of-13.2 V and-950 nA was further achieved by connecting two harvesters in series and parallel, respectively. Origin of the harvesting enhancements was believed to be associated with extra space-charge polarization and the content of 8-phase. The core-shell devices were also successfully demonstrated as tactile sensors to electrically detect various body motions.

Automated summary

Polymer nanofiber-based core-shell piezoelectric energy harvesters show superior performance with the thinnest shell layer exhibiting the best output performance. Further enhancements in performance were achieved by connecting two harvesters in series and parallel, and the devices were successfully demonstrated as tactile sensors for detecting various body motions with electric signals.