Biomimetic Elliptical Apertures in Nanofiber Transducers for Intrinsically Broadband and Flat Acoustoelectric Sensing

ABSTRACT Inspired by the elliptical biomechanics of the human eardrum, this study presents a novel design that enables nanofiber acoustoelectric sensors to achieve a flat, broadband frequency response without electronic equalization. Integrating electrospun polyacrylonitrile (PAN) nanofiber membranes with biomimetic elliptical aperture electrodes disrupts structural symmetry. This configuration significantly promotes higher‐order, multi‐nodal vibrations along the device's major axis, leading to resonance superposition. A single‐aperture device delivers a flat response from 270 to 518 Hz (Δ f = 248 Hz) with an output voltage of 9.93 ± 0.74 V. A linear array of five apertures extends the flat bandwidth to 219–676 Hz (Δ f = 457 Hz), increasing the output voltage to 14.62 ± 0.92 V through enhanced inter‐aperture coupling. The sensors achieve a signal‐to‐noise ratio of 45.9 dB and a spectral distortion of 7.52 dB, enabling 98.7% vowel recognition and 100% speaker identification accuracy. It can also be used as an energy harvester to power microelectronics and recharge energy storage devices. This study establishes a geometry‐dominated paradigm for purely passive broadband sensing, paving the way for high‐fidelity voice interfaces and voiceprint authentication systems.