Inspired by the natural soundproofing prowess of owls, a recent study published in ACS Applied Materials & Interfaces introduces a groundbreaking two-layer aerogel designed to mimic the intricate structures found within owl skin and feathers. This innovative material has the potential to revolutionize noise reduction technology, offering applications in areas such as automotive engineering and industrial manufacturing to combat the detrimental effects of sound pollution.
The detrimental effects of noise pollution extend beyond mere annoyance, with prolonged exposure leading to serious health issues such as hearing loss, cardiovascular disease, and diabetes. While eliminating noise sources is often challenging, the use of soundproofing materials can help mitigate these effects. Traditional soundproofing materials are typically specialized to absorb either high- or low-frequency sounds, necessitating the use of multiple layers to achieve comprehensive noise control. This approach adds bulk and weight to the structure, making it less efficient and practical.
To address this limitation, Dingding Zong and a team of researchers sought inspiration from the owl’s exceptional acoustic abilities. By emulating the soft feathers and porous skin of owls, the researchers aimed to create a versatile sound absorber capable of effectively dampening noise across a broad spectrum of frequencies.
The research team employed a unique technique known as emulsion-templated freeze-reconstruction to freeze hexane droplets within a soft material, resulting in a honeycomb-like pattern upon removal. A second layer featuring silicon nanofibers was added to create a fibrous structure, mimicking the intricate patterns found in owl feathers.
The resulting two-layer aerogel closely resembles the acoustic properties of owl skin and feathers, with the porous bottom layer canceling out low-frequency noise through microscopic cavities, while the top layer composed of fluffy nanofibers effectively dampens high-frequency sounds.
In their experiments, the researchers observed that the owl-inspired aerogels exhibited impressive sound absorption capabilities, including absorbing 58% of incoming soundwaves and reducing automobile engine noise by 87.5 decibels to a safer level of 78.6 decibels. Furthermore, the aerogels maintained structural integrity even after 100 compression cycles, experiencing only 5% deformation.
This groundbreaking study opens new possibilities for the development of lightweight, durable, and high-performance sound-absorbing materials that have the potential to significantly reduce noise pollution from industrial machinery and vehicular traffic.
More information:
Yaning Sun et al, Owl-Inspired Coupled Structure Nanofiber-Based Aerogels for Broadband Noise Reduction, ACS Applied Materials & Interfaces (2025). DOI: 10.1021/acsami.5c04691
