Highly aligned P(VDF-TrFE) nanofibers for tactile and flow-sensing applications

Lead-free piezoelectric polymer materials offer an attractive proposition for developing sustainable wearable devices. In this work, we report electrospun Poly(vinylidene fluoride-co-trifluoroethylene)-based self-powered sensors for tactile sensing and flow sensing. The work entails the optimization of the electrospinning process for developing highly aligned nanofibers with high electroactive β-phase content for developing piezoelectric self-powered sensors. A series of morphological and material characterization experiments were conducted to improve the alignment of the electrospun nanofibers and achieve high β-phase content (∼ 80%). The optimized recipe was used for developing a tactile sensor capable of detecting force in the range of 1 - 50 N while maintaining good linearity and a force sensitivity of ∼ 0.74 V/N. Finally, the highly aligned nanofibers were spun onto a 3D-printed substrate entailing a pair of raised micropillars with integrated electrodes, and the assembly was employed for oscillatory flow sensing in water.