Enhancing piezoelectric performance of PVDF-TrFE nanofiber sensors via PPy@BT doping for monitoring finger rehabilitation in Parkinson’s disease

To address the lack of non-invasive real-time monitoring of hand motor symptoms in Parkinson’s disease, this study proposes a flexible piezoelectric sensor that detects electrical signal responses generated under different finger bending angles and frequencies, which can be used to monitor and evaluate finger motor function and rehabilitation training in patients with Parkinson’s disease. Moreover, the sensor maintains stable output over seven days and exhibits good biocompatibility. A doping strategy employing polypyrrole-coated BaTiO 3 (PPy@BT) nanoparticles is used to significantly enhance the piezoelectric performance of poly(vinylidene fluoride-trifluoroethylene) (PVDF-TrFE) nanofiber sensors. PVDF-TrFE/PPy@BT composite nanofiber membranes are prepared by electrospinning and assembled into a flexible piezoelectric nanogenerator (PENG). The microstructure, dielectric properties, mechanical, and piezoelectric performance of the composite are systematically characterized. Experimental results demonstrate that, under optimal doping conditions, the PENG exhibits an open-circuit voltage of 13.64 V, which corresponds to approximately 455% of the value of the undoped PVDF-TrFE membrane. Furthermore, the device maintains a stable output over 3000 cyclic loadings. The device achieves a maximum sensitivity of 39.34 V·kPa⁻ 1 in the low-pressure region (0–1 kPa) and delivers a peak power density of 0.32 W·m⁻ 2 at a load resistance of 10 8 Ω, demonstrating its excellent energy conversion efficiency.