Flexible Piezoelectric Fibers for Acoustic Sensing and Positioning

Emerging development of flexible acoustic devices focuses on constructing large‐area acoustic sensing networks with high spatial and temporal resolution, enabling applications in acoustic sensing and positioning, particularly in underwater and medical fields. Here, a piezoelectric fiber‐like device is fabricated by a thermal drawing technique to deliver acoustic sensing functionalities at fiber‐optic length scales, flexibility, and uniformity. The resulting piezoelectric fiber device operates in a frequency range of 2–8 MHz with signal‐to‐noise ratio above 20 dB. Additionally, a single piezoelectric fiber can simultaneously demodulate two monochromatic sound signals with a frequency gap from 0.01 to 30 MHz. As a proof of concept, a 2D 3 × 3 fiber array is fabricated to detect and position an underwater acoustic source with a spatial resolution of one centimeter.