01984nas a2200181   4500008004100000022001400041245008600055210006900141260001600210300001600226490000800242520141700250100001801667700002101685700001901706700002601725856005101751       2018                        eng d  a0001-496600aThe micromechanics and bioacoustic behaviour of <i>Bunaea alcinoe</I> moth scales0 amicromechanics and bioacoustic behaviour of iBunaea alcinoeI mot  cJan-09-2018  a1775 - 17750 v1443 a<p>Through the 65 million year acoustic arms race between moths and bats, different moth species have evolved different defence strategies against bat echolocation. For non-toxic moth species without hearing capability, passive acoustic camouflage is thought to be the most efficient way to evade bat predation. Being the elementary building blocks covering moth wing surfaces, scales have been hypothesized as the main organ creating such acoustic camouflage. There is, however, no understanding for the relation between scale microstructure and wing acoustic performance. This report represents the first effort to numerically and experimentally characterize moth scale biomechanics and vibrational behaviour. 3D microstructures of Bunaea alcinoe moth scales have been characterized using various microscopies. A parameterized finite element model has been built to replicate the double-layered perforated scale bio-nanomaterial. Both experimental and numerical analyses have proved that the first three resonance frequencies of a single scale lie within the bat echolocation frequency range. Here, we propose numerical models that explain how the resonances can contribute to the acoustic performance of wings. This study contributes to the on-going discussion of the evolution of ultrasonic camouflage in moths. We aim to use our findings to generate biomimetic light-weight noise mitigation materials.</p>
1 aShen, Zhiyuan1 aNeil, Thomas, R.1 aRobert, Daniel1 aDrinkwater, Bruce, W.  uhttp://asa.scitation.org/doi/10.1121/1.5067852