Fabrication of core-sheath nanoyarn via touchspinning and its application in wearable piezoelectric nanogenerator

A simple and versatile touchspinning method is demonstrated for the fabrication of core-sheath nanofibrous piezoelectric yarns with a single filament electroconductive core. The polyvinylidene fluoride (PVDF) piezoelectric nanofibers are fabricated in a continuous spinning process with relatively controlled structure, orientation, and dimensions to form a sheath layer. The PVDF core-sheath nanoyarn is assembled into a piezoelectric nanogenerator (PNG) capable to convert mechanical energy of body motion into electricity. It was demonstrated that an electrical potential difference of 0.72 V can be generated under compression of 0.33 MPa for a single 3-cm long yarn. The touchspun nanoyarn fabrication method has great potential for the fabrication of functional smart textile products.