Enhanced Acoustoelectric Energy Harvesting with Ti₃C₂T_x MXene in an All-Fiber Nanogenerator

Materials and devices that harvest acoustic energy can enable autonomous powering of microdevices and wireless sensors. However, traditional acoustic energy harvesters rely on brittle piezoceramics, which have restricted their use in wearable electronic devices. To address these limitations, this study involves the fabrication of acoustic harvesters using electrospinning of the piezoelectric polymer PVDF-TrFE onto fabric-based electrodes. Two-dimensional (2D) Ti₃C₂T_x MXene flakes were used to induce polarization locking of the electrospun PVDF-TrFE for optimal electromechanical performance of PVDF-TrFE. The mechanically robust, lightweight, and flexible device was demonstrated to detect and harvest energy in the sound frequency range of 50 to 1000 Hz at sound levels between 60 and 95 dB, while exhibiting a high sensitivity of 37 VPa^-1, which is higher than previously reported values for PVDF-based sound harvesters. The maximum output power can reach 19 mW/cm³ under 200 Hz and 95 dB. The development of this material opens a future pathway for powering small electronic devices, such as implantable biomedical devices, smart wearable technology, and remote Internet-of-Things devices.