A Broadband High-Output Acoustoelectric Transducer Based on Electrospun BTO/PVDF-HFP Nanofiber

The efficient conversion of ambient acoustic energy into electrical power has attracted considerable research interest for its potential to sustainably power microelectronics and self-powered sensors. Nevertheless, the development of an acoustoelectric transducer that simultaneously delivers broadband response, high conversion efficiency, and substantial power output remains a pressing challenge. Herein, we report a broadband high-output acoustoelectric transducer. The device architecture features an electrospun barium titanate (BTO)/poly(vinylidene fluoride-hexafluoropropylene) (PVDF-HFP) nanofiber membrane, sandwiched between two gold-coated poly(ethylene terephthalate) electrodes with a precisely engineered air spacer. Upon acoustic wave excitation, the membrane and electrode exhibit contact-separation motion, simultaneously exciting both piezoelectric and triboelectric effects. The optimized device, comprising a 0.5 mm air spacer and a 3% BTO-doped PVDF-HFP nanofiber membrane, achieves a peak output of 410.28 V and 50.24 μA under 115 dB acoustic excitation at 170 Hz. The instantaneous maximum power density reaches 11576.12 μW/cm3 (the peak surface power density is 845.06 μW/cm2). The electrical energy generated can directly power miniature electronic devices without additional energy supplying equipment. This structure effectively converts acoustic waves into an electric signal from 1 to 5000 Hz (including infrasound). Therefore, the device holds potential for detecting and warning against natural disasters associated with infrasound emissions. This acoustoelectric transducer thus exhibits promising application prospects in noise energy recovery, environmental monitoring, self-powered systems, speech recognition, and human-computer interaction.