Flexible Piezoelectric Pressure Tactile Sensor Based on Electrospun BaTiO₃/Poly(vinylidene fluoride) Nanocomposite Membrane

Poly(vinylidene fluoride) (PVDF)-based piezoelectric materials are promising candidates for sensors, transducers, and actuators, due to several distinctive characteristics such as good flexibility, easy processability, and high mechanical resistance. In the present work, PVDF-based nanocomposites loaded with BaTiO₃ nanoparticles (NPs) of various weight fractions were prepared by the electrospinning technique and used for the fabrication of a flexible piezoelectric pressure tactile sensor (PPTS). The addition (5, 10, and 20 wt %) of piezoelectric BaTiO₃ NPs improves the piezoelectric performance, especially the β phase crystals of PVDF/BaTiO₃ (10 wt %) nanocomposites that can reach 91.0%. In addition, the mechanical strength of PVDF/BaTiO₃ nanocomposites is up to 26.7 MPa, which is an increase of 66% compared to neat PVDF. It should be emphasized that the elongation at break continuously increases from 71% to 153% with increasing BaTiO₃ NPs. More importantly, the PPTS (piezoelectric pressure tactile sensor) with the combination of electrospun PVDF/BaTiO₃ nanocomposite membranes and polydimethylsiloxane (PDMS) displays excellent flexibility and linear response to external mechanical force. The flexible PPTS devices capable of detecting different music sounds have potential uses in wide fields, such as voice recognition, speech therapy, and ultrasound imaging.