Acoustoelectric Conversion Properties of Piezoelectric Polyamide-imide Nanofiber Membranes

Electrospun polyamide imide (PAI) nanofibers have demonstrated exceptional piezoelectric performance in both ambient and high temperature environments. Despite these advances, their potential for acoustoelectric conversion remains unexplored. This study systematically investigates the acoustoelectric capabilities of electrospun PAI nanofiber membranes. A device was constructed by sandwiching the nanofibers between aluminum foil electrodes with straight, narrow slits. When tested under sound conditions of 350 Hz and 126 dB, a 52 ± 2 μm thick PAI membrane (diameter 754 ± 77 nm and working area 3 × 4 cm2) produced a peak-to-peak open circuit voltage (Voc-pp) of 52 ± 0.59 V. At 100 Hz and 117 dB, the Voc-pp increased to 56.4 ± 0.26 V (power density, 27.56 μW/cm2). The PAI devices maintained stable operation in the temperature range from up to 195 °C, exhibiting significantly higher thermal stability compared to PVDF and PAN nanofiber counterparts. These results position electrospun PAI nanofibers as a promising material for advanced acoustoelectric transduction, with significant potential in applications such as sound detection and acoustic energy harvesting technologies. The high thermal stability and large electrical output enable acoustoelectric PAI nanofibers to reliably detect sound in elevated environments, such as automobiles, industrial machinery, and firefighting situations, making them ideal for high-temperature acoustic sensing applications.