High-Performance Voice Recognition Based on Piezoelectric Polyacrylonitrile Nanofibers

Acoustic sensors show a wide application in diverse fields. However, it is still a challenge to develop highly sensitive transducing materials for the detection of low-to-middle decibel sounds. Herein, for the first time the remarkable property of an acoustic sensor based on electrospun polyacrylonitrile (PAN) nanofibers in the recognition of human voices is reported. The nanofiber device shows a sensitivity as high as 23 401 mV P⁻¹ to 70 dB sound, which is much higher than most of the acoustic sensors reported in the literature. First the sounds from different musical instruments are used as a standard sound source to show the high accuracy of the nanofiber device to distinguish different sounds, e.g., from both the same and different instruments, and then people's voices are tested. Experimental results show that the device can distinguish people's voices with high resolution and the influence of background noise on speech recognition is very small. The acoustic sensor is stable and can be used in sound detection for a long time. Electrospun PAN membranes may be useful for the development of voice recognition systems for security, environmental protection, scientific research, and other high-tech applications.