Toward a Bio-Inspired Acoustic Sensor: <i>Achroia grisella’s</i> Ear

Gathering insights from nature to develop original solutions for engineering problems is known as bio-inspiration. The examples found in are often efficient and beautifully simple. For the particular issue of directional acoustic sensing at small scales, insects provide a myriad clever adaptations achieve hearing despite their body size. Achroia grisella nocturnal moth capable wavelengths significantly longer than its intertympanic distance. Previous studies have shown that directionality this monoaural exclusively relies on shape eardrum itself. work developed computer model behaves similar moth’s ear, which then 3-D printed. starts simplified circular membrane progresses until it reflects tympanum more closely. approach consists four steps: considering analytical equations, virtually simulating model, manufacturing performing experimental measurements, finally comparing outcomes each. Equations produced simplest geometries, COMSOL Multiphysics used simulations. samples manufactured via printing excited with vibrating piezoelectric chip speaker while being measured laser Doppler vibrometer determine frequency responses.