Electrospun P(VDF-TrFE):LiClO₄ Hybrid Nanofiber-Based Highly Sensitive Piezocapacitive Pressure Sensors for Self-Powered Flexible Electronics

Piezoelectric materials are extensively utilized in energy harvesters, accelerometers, dynamic pressure sensing, and pulse sensing applications. Here, we developed a flexible piezocapacitive pressure sensor utilizing electrospun P(VDF-TrFE):LiClO4 (polyvinylidene fluoride-co-tetrafluoroethylene: lithium perchlorate) hybrid nanofibers for innovative sensing applications. The developed sensor offers an alternative technique for overcoming the constraints of conventional pressure sensors by employing the distinctive piezoelectric properties of P(VDF-TrFE) nanofibers and enhanced electric conductivity due to doped lithium perchlorate (LiClO4). The excellent sensing, enabled by the incorporation of LiClO4 in P(VDF-TrFE), was extensively investigated through multiscale testing. Piezoresponse force microscopy (PFM) and a d33 piezometer were used to assess the piezoelectric characteristics of nanofibers. The P(VDF-TrFE):LiClO4 hybrid nanofibers have shown ∼21% enhancement in the piezoelectric coefficient (d33) and a substantial increase in output voltage (∼1.4 V) for an optimal concentration of LiClO4 (5 w/v%). Functionality of the developed sensory system has been demonstrated by precisely monitoring the radial artery pulse pressure and measuring capacitance versus time waveform that was analogous to arterial pulse dynamics. This technique highlights the potential of P(VDF-TrFE):LiClO4 nanofiber-based sensors for real-time noninvasive health monitoring. The prototype sensor exhibits a rapid response and relaxation time of ∼20–30 ms and a sensitivity of 6.639 kPa–1. The developed pressure sensory system opens the way for next-generation wearable biomedical devices, establishing a benchmark for future advancement in E-skin, wearable electronics, medical surveillance, and automation systems.