The researchers, who recently discovered that moth wings offer acoustic protection from bat echolocation calls, have been studying whether their structure could inform better performing sound absorbing panels when not moving in free space.

Bats and moths have been involved in an acoustic arms race between predator and prey ever since bats evolved echolocation some 65 million years ago. Moths are under huge predation pressure from bats and have evolved a plethora of defenses in their strive for survival, but it’s the scales on a moth wing that hold the key to transforming noise-canceling technology. [1]

Figure 1. Moth wing–inspired sound absorbing wallpaper in sight after breakthrough

Figure 1 shows Prof. Holderied and his team tested this by placing small sections of moth wings on an aluminum disk, then systematically tested how orientation of the wing with respect to the incoming sound and the removal of scale layers affected absorption.

Remarkably, they found that moth wings proved to be excellent sound absorbers, even when on top of an acoustical solid substrate, with the wings absorbing as much as 87% of the incoming sound energy. The effect is also broadband and omnidirectional, covering a wide range of frequencies and sound incident angles. [2]

“This extraordinary performance qualifies the moth wing as a naturally occurring acoustically absorbent meta-surface, a material with unique properties and capabilities not possible with conventional materials.”

The potential of making ultra-thin sound-absorbing panels has huge implications for the acoustics of buildings. As cities get louder, the need for efficient, non-intrusive noise mitigation solutions grows. [4]

Now the scientists plan to replicate the sound absorbing performance by designing and building prototypes based on the sound absorbing mechanisms of the moth. The absorption that they have characterised in moth wing scales is all in the ultrasound frequency range, above that which humans can hear. Their next challenge is to design a structure that will work at lower frequencies whilst retaining the same ultrathin architecture employed by the moth.  [3]

References:

1. https://mixpoint.in/biotechnology/2022/06/moth-wing-inspired-sound-absorbing-wallpaper-in-sight-after-breakthroug
2. https://phys.org/news/2022-06-moth-winginspired-absorbing-wallpaper-sight.html
3. https://www.bristol.ac.uk/news/2022/june/moth-wing-inspired-sound-absorbing-wallpaper.htm
4. https://whatsnew2day.com/moth-wing-inspired-sound-absorbing-wallpaper-in-sight-after-breakthrough

Cite this article:

Thanusri swetha J (2022), Moth wing–inspired sound absorbing wallpaper in sight after breakthrough, Anatechmaz, pp.166