A Cantilever-Based Broadband Acoustoelectric Device with Aligned PVDF-HFP Nanofibers for Self-Powered Sensing and...

As the adoption of acoustic sensing grows in speech recognition, health monitoring, and the Internet of Things, the limited broadband response of flexible acoustic sensors has become a significant challenge. This study presents a novel acoustoelectric device featuring a cantilever-based electrode structure. By designing an electrospun aligned PVDF-HFP nanofiber piezoelectric active layer alongside a gold-coated film electrode with cantilever architecture, the device achieves a triple coupling mechanism of acoustic, mechanical, and electrical interactions, leading to enhanced performance. Under 110 dB sound pressure, the 12 × 8 mm² cantilever-area device demonstrates an extended operating bandwidth of up to 800 Hz, a peak voltage of 33.55 V, and high sensitivity within the 60-110 dB sound pressure range (74.25 mV·Pa^-1 at 1000 Hz, 94 dB SPL and 8.13 V·Pa^-1 at 170 Hz, 100 dB SPL). It attains a voice capture signal-to-noise ratio of 61.50 dB and a machine learning-based speech recognition accuracy of 98.5%. This work establishes a new paradigm for broadband acoustic device design and advances the practical application of high-fidelity human-computer interaction and intelligent sensing technologies.