Fabrication and Piezoelectric Output Characterization of MXene-Modified Poly(vinylidene fluoride-co-trifluoroethylene) Composite Films

Flexible piezoelectric nanogenerators (PENGs) have garnered significant interest for their high sensitivity in harvesting mechanical energy into electrical power, particularly as self-powered sensors for human motion monitoring. In this work, MXene-doped poly(vinylidene fluoride-co-trifluoroethylene) [P(VDF-TrFE)]-based piezoelectric nanofiber composite films were fabricated via electrospinning. Upon identifying the optimal MXene doping ratio of 4 wt%, a layered architecture was engineered through a uniaxial intermittent alternating dual-spray method. The composite film with 3-5 wt% MXene exhibited exceptional piezoelectric performance, achieving an output voltage of 11.91 V, representing a 259% enhancement over pristine P(VDF-TrFE)) and a current density of 0.98 μA. The peak instantaneous power output reached 11.67 μW, corresponding to a power density of 3.89 μW/cm². Remarkably, the output stability was maintained over 1,000 mechanical cycles, demonstrating robust mechanical durability. The fabricated flexible sensor successfully monitored human joint movements and illuminated micro-LEDs, highlighting its potential for wearable electronics and energy harvesting applications.