Towards a bio-inspired acoustic sensor: Achroia grisella’s ear

Bio-inspiration looks to nature to overcome challenges innovatively. Insects show many examples of efficient approaches to hearing considering the small sizes of their bodies. The nocturnal moth Achroia grisella is capable of directional hearing of wavelengths several times larger than the separation between its tympana. Directionality in this moth seems to be monoaural and dependent exclusively on morphology, so a model is developed to replicate the structure. We start from a simple circular model, progressively incorporating more complex elements to improve the resemblance to the natural system. The goal is to develop a model inspired by Achroia’s ear, that behaves similarly to it, and to 3D print devices that agree with the model. Equations, simulations, and 3D printed devices measured through Laser Doppler Vibrometry are compared.