Boosted output of flexible PANI@BTO/PVDF–TrFE piezoelectric nanogenerators for self-powered multifunctional sensing in wearable systems

The integration of human–machine interaction (HMI) technologies into patient rehabilitation is attracting growing attention, with portable, inexpensive, skin-conformal, and wearable low-power electronic devices being the preferred choice for such applications. Piezoelectric nanogenerators (PENGs), are particularly promising owing to their flexibility, self-powered ability and compatibility with wearable systems, holding significant potential for the next generation of flexible electronics. A flexible PVDF-TrFE composite film reinforced with in situ synthesized PANI@BTO was developed via interfacial engineering. The optimized composite exhibited an outstanding remanent polarization of 12.4 μ C cm −2 and a superior piezoelectric coefficient of 74.3 pm V −1 , together with stable performance over 7000 mechanical loading cycles. The corresponding device generated an output voltage of 12.2 V and a current of 1 . 9 μ A under an applied pressure of 111.1 kPa, underscoring its highly efficient energy conversion capability. The developed noninvasive, high-sensitivity sensor was successfully applied to monitor biomechanical activities such as joint motion and pulse. Furthermore, an advanced virtual reality (VR) based-motion interactive serious game platform was successfully developed, integrating the advanced sensor with wireless communication and signal processing modules for assisted knee rehabilitation. This work highlights the broad potential of flexible piezoelectric nanogenerators in next generation self-powered sensing healthcare monitoring and human-machine interactive systems. • In situ PANI@BTO core–shell fillers boost interfacial polarization. • High P r (12.4 μ C cm −2 ) and d 33 (74.3 pm V −1 ) achieved in PVDF–TrFE composites. • Flexible PENG delivers 12.2 V and 1 . 9 μ A under 111.1 kPa loading. • Self-powered sensor enables motion and pulse monitoring. • VR-based interactive platform demonstrated for knee rehabilitation.