OWLS silent flight inspires new noise reduction technology

If you have seen an owl flying, you have probably heard nothing. Indeed, their skin and feathers amortize the sound by absorbing high and low frequency flight noise.

Inspired by this natural soundproofing, researchers publish APS materials and interfaces to have developed A two -layer aerogel that imitates structures inside owl feathers and skin to alleviate healthy pollution. This new equipment could be used in cars and manufacturing facilities to reduce traffic and industrial noise.

Noise pollution is more than a nuisance; Excessive noise can lead to hearing loss and can worsen health problems such as cardiovascular disease and type 2. diabetes. When the elimination of the source of noise pollution is not possible, soundproofing materials help to amortize it. However, Traditional materials Absorb either high frequency sounds, such as flowing brakes or low frequency sounds, such as the deep rumble of a car engine. This means that engineers often overlap several types of soundproofed materials to obtain complete spectrum noise control, which adds weight and bulk.

To overcome this, Dingding Zong and his colleagues turned to an unlikely acoustic expert: The Owl. The owl uses its soft feathers and porous skin to stay whished during the flight. The researchers’ objective was to design an absorber with a similar broadband sound.

The researchers frozen hexane droplets in a layer of flexible material, using a technique called freezing regelation supported by emulsion. The withdrawal of frozen hexane revealed a honeycomb type motif in the material. They added a second layer with silicon nanofibers instead of hexane droplets to create a fibrous pattern.

Light light, porous and two -layer aerogel imitates structures of owl skin and feathers: The lower porous layer looks like the bird skin with microscopic cavities that cancel noise at low frequency; and the upper layer of pen inspiration, made of fluffy nanofibers, reduces high frequency sounds.

In particular, researchers have found that their hubs inspired by the owl can:

• Absorb 58% of the sound waves that strike it, exceeding the threshold of effective noise control materials.
• Reduce 87.5 noise decibels of the car engine to a safe level of 78.6 decibels, which is a better reduction than existing high -end noise absorbers.
• Maintain structural integrity through 100 compression cycles, with only 5% deformation.

Researchers think that this study opens the way to high performance, light and durable materials which can considerably mitigate sound pollution of industrial equipment and traffic.