Enhanced poling efficiency via a maximized organic-inorganic interfacial effect for water droplet-driven energy harvesting

Piezoelectric fluoropolymers that can convert mechanical energy to electricity have attracted intensive attention in sustainable power sources for microelectronics. However, in order to achieve high energy conversion efficiency in fluoropolymers, an electrical poling under a high electric field is an unavoidable high energy-consumption process. Herein, we demonstrated the enhanced poling efficiency in nanocomposite made of poly(vinylidene fluoride-co-trifluoroethylene) (P(VDF-TrFE)) and porous BaTiO₃ nanofibers (BT NFs). The high specific surface area of porous BT NFs maximized the P(VDF-TrFE)-BT interfacial region, which produces rapid reorientation of dipole moments under electric field; this behavior effectively improved the poling efficiency of the piezoelectric nanocomposite. Subsequently, we fabricated an flexible piezoelectric nanocomposite generator (PNCG), which generated an open-circuit voltage of ~13.1 V and a short-circuit current of ~2.0 μA with a relatively low electric field of 200 kV cm⁻¹. Furthermore, the PNCG is realized in a real-world environment and generates sufficient power to charge a commercial capacitor by harvesting mechanical energy from falling water droplets. This work provides a low-energy consumption pathway for developing high-performance piezoelectric devices for practical applications.