Piezoelectric nanofibers for self-powered pacemaker: a flexible, functional, and sustainable approach

Self-sustaining cardiac pacemakers require reliable and biocompatible energy sources that can transform physiological motion into electrical energy. Energy harvesting from body motion is promising for cardiac pacemaker applications. A spiral piezoelectric energy harvester was numerically analyzed using FEM COMSOL for different turns, fabricated, and tested for electrical output. Electrospinning induced dipole alignment and β phase crystallization, yielding ~ 68% electroactive phase content and improved piezoelectric properties. The PVDF mat showed a force-proportional voltage response and an output of 18.3 ± 0.78 V at 0.5 N and 10 Hz during mechanical stimulation. Calculated piezoelectric coefficients (d₃₃ = 29.6 ± 0.89 pC/N, d₃₁ = 13 ± 0.61 pC/N) and ferroelectric properties (P_r = 0.16 μC/cm2, E_c ≈ 280 kV/mm) confirmed effective electromechanical coupling. The nanofiber generator attained a peak power density of 16 μWcm⁻² at 4 MΩ. A computer analysis of a three-turn spiral cantilever revealed a resonance frequency of 30.6 Hz, representing a 54.93% reduction compared to a two-turn design, which nearly corresponds to the human pulse spectrum. At the resonance frequency, the PVDF energy harvester generated an output power of 5.3 mW and a power density of 14.4 μWcm⁻², which is higher than that of a ZnO-based device. Experimental results confirm PVDF-based spiral harvesters as an efficient self-powered energy source for cardiac pacemakers.