How a moth’s wings could make your home quieter
Noise is an important part of our home environment. The most beautiful, well-designed home, if situated next to a busy, noisy road, falls in value due to its location, location, location. Apartments in the city may have beautiful balconies that are never used because of the drone of traffic all around. What if nature offered an innovative sound-absorbing “cloak” for your home?
Bats use echolocation to find their prey. Smooth surfaces that lack scales or fur make the echoes louder, allowing the bat to close in quickly. Animals with fur or scales, however, can elude the bat more often. Scientists have discovered that a certain type of moth have scales that overlap in unique ways to provide exceptional sound-dampening.
Diamond Light Source is a synchrotron in the UK (a synchrotron is a circular particle accelerator), which was used to examine the nanosized scales on the wings. According to Professor Christoph Rau, a scientist at this synchrotron, the sound absorbing properties of thoracic moth scales are capable of absorbing about two thirds of the sound energy emitted by their predator, the bat, and significantly increases the insect's survivability.
A separate study by the University of Bristol's School of Biological Sciences showed that the wings absorb 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.
"What is even more impressive is that the wings are doing this whilst being incredibly thin, with the scale layer being only 1/50th of the thickness of the wavelength of the sound that they are absorbing," explained lead author Dr. Thomas Neil.
What could we do with such incredible sound-absorbing performance? Certain types of noise, like car horns and screeching tires can be detrimental to our health, as we detailed in this article. Then, there’s also the noise pollution that comes from neighbors or even your own home, which can affect your sleep or concentration while studying or working from home. Wallpaper or ultra thin sound absorbing panels would vastly improve interiors or exteriors in cities and other loud locations. Office walls and places where highly sensitive information is discussed could use it. Even libraries, children’s nurseries and our own bedrooms could use it. Can you get too much quiet in a space? I don’t think so, when the world’s noise is only a few steps away!