High performance flexible piezoelectric sensor based on P(VDF-HFP)/ boron nitride/graphene oxide composite film for smart clothing

In this study, polyvinylidene fluoride-hexafluoropropylene (PVDF-HFP) was used as the matrix, different percentages of Boron Nitride (BN) and Graphene Oxide (GO) were added to P(VDF-HFP), piezoelectric nanofiber films were prepared using electrospinning technology. Through a series of tests, it was determined that the composite film with 2 % BN and 4 % GO exhibited the best piezoelectric effect. The β-phase content increased from 76.01 %, to 98.48 %. The remanent polarization increased from 0.029 μC/cm² to 0. 098 μC/cm², BN and GO synergistically enhanced the piezoelectric effect of P(VDF-HFP) film, the presence of GO induces the transformation of BN from multilayer to monolayer, which breaks the inverse symmetry of BN and thus enhances the piezoelectric effect, and the presence of GO increases the flow of electrons between the nanomaterials. While the B atoms in the BN interact with the F atoms in P(VDF-HFP), which promotes the enhancement of the β-phase in the PVDF-HFP. The piezoelectric film was made into piezoelectric sensor, under a force of 2 N, the piezoelectric output increased from 1.5 V to 7.3 V, the sensitivity increased from 0.722 V kPa⁻¹ to 3.068 V kPa⁻¹. The manufactured piezoelectric sensor exhibits fast response and recovery times (13.66/19.25 ms), after 7000 cycles of testing, the sensor maintained good stability. The developed piezoelectric sensor can detect human motion states, sense the temperature and harvest high-entropy energy to power electronic watches, showing promising potential for applications in smart clothing.