High-Performance Fiber Optic High-Frequency Cantilever Acoustical Transducer Based on PET Film

In this article, a high-performance fiber optic polyethylene terephthalate (PET) cantilever acoustic transducer (PET-CAT) is reported for weak acoustic signal sensing. The PET cantilever is manufactured by laser marking machines. The Young modulus of the PET-CAT used is roughly 40 times lower than that of conventional stainless-steel cantilever, resulting in higher acoustic pressure detection sensitivity. The theoretical and simulation analysis has been carried out to design the PET-CAT for high-performance acoustic sensing. Experiments have shown that the sensitivities of the PET-CAT reach up to 8004.6 nm/Pa at 2823 Hz and 605 nm/Pa at 3300 Hz. The equivalent noise sound pressure (ENSP) is <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$2.48~\mu $ </tex-math></inline-formula> Pa/Hz<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$^{\text {1/2}}$ </tex-math></inline-formula> at 3300 Hz. The proposed PET-CAT, featuring compact size, low cost, simple processing, chemical stability, high sensitivity, and strong resistance to electromagnetic interference, is suitable for high-frequency weak signal long-distance sensing.