Sensing viscous acoustic flow: Using spider silk to hear

Measurements obtained with a laser vibrometer show that a single strand of spider silk captures sound with almost full fidelity across a broad frequency range from infrasound to ultrasound, surpassing the performance of any known microphone or ear. The high responsivity of the silk to acoustic particle velocity enables the orb-weaving spider to hear sounds from meters away by utilizing its web—a hearing mechanism distinct from that of other animals that rely on an organ within their body. Laser-based measurements have also revealed that small creatures like mosquitoes can hear far-field sounds, similar to the spider, by sensing acoustic particle velocity rather than pressure. These findings offer insights for designing novel acoustic flow detectors and have led to the development of a recently commercialized flow microphone.