Ion dipole interaction and directional alignment enabled high piezoelectric property polyvinylidene fluoride for flexible electronics

Organic piezoelectric materials have attracted significant interest for applications in sensing, energy harvesting, and flexible electronics. However, its piezoelectric properties are yet to be improved. This study introduces a facile strategy to fabricate homogenous and dense polyvinylidene fluoride (PVDF) films with high piezoelectric performance via anhydrous CaCl2 doping. The strong ion–dipole interaction between Ca2+ and F atoms, along with directional dipole alignment under an electric field at elevated temperature, as verified by molecular dynamics simulations and material characterizations. This results in an impressive β-phase content of 92.78% and a piezoelectric coefficient of 29.26 pm/V. A piezoelectric device fabricated from this PVDF film delivers an output voltage exceeding 12 V under external pressure and maintains stability over 60,000 cycles. When integrated with an LC resonant circuit, it functions as a wireless sensor for real-time motion monitoring. This scalable approach significantly advances piezoelectric polymer performance for practical applications.