Researchers have fabricated a hair-thin microphone made entirely of silica fiber that can detect a large range of ultrasound frequencies beyond the reach of the human ear. Able to withstand temperatures up to 1,000°C, the device could eventually be used inside high-voltage transformers to detect early signs of failure before power outages occur.
“Conventional electronic sensors often fail under thermal stress or suffer from severe signal interference,” said Xiaobei Zhang, a member of the research team from Shanghai University. “Our all-fiber microphone can survive in hazardous environments and is completely immune to electromagnetic interference while remaining sensitive enough to hear the subtle early warning signals of equipment failure.”
In an article published in Optics Express, the researchers describe their new microphone, which is sensitive to frequencies from 40 kHz to 1.6 MHz. Unlike traditional microphones that rely on bulky housing, the new microphone is entirely integrated within a fiber just 125 microns in diameter.








