A New Material Can Soften the Roar of Aircraft to Hairdryer Levels

If you live in a major city, you are probably keenly aware of the roar of aircraft flying overhead.

In the last century, aircraft have grown so incredibly loud that major metropolitan neighborhoods have reduced prices to sweeten a noisy deal. But a new material might one day change all of this and cut down on the periodic wane of jet engines.

A team of scientists has developed a new and remarkably lightweight material capable of insulating aircraft engines and reducing noise by up to 16 decibels, cutting the 105-decibel scream of jet engines taking off to the level of a hairdryer, according to a recent study published in the journal Scientific Reports.

And the new insulating material could roll out in the next 18 months.

New aircraft engine insulator is extremely lightweight

The novel material is a graphene oxide-polyvinyl alcohol aerogel, and weighs only 2.1 kg per cubic meter, significantly lighter than other sound insulating materials. Notably, the aerosol takes the form of a meringue-like structure, which makes it light enough to work as an insulator from within aircraft engine nacelles, adding almost no extra weight. As of writing, the research team is continuing to optimize the material, with hopes of enhancing its heat dissipation capabilities, which would prove a boon to safety and fuel efficiency.

The study came from the University of Bath's Materials and Structures Center (MAST), and could augment the entire aviation industry. "This is clearly a very exciting material that could be applied in a number of ways — initially in aerospace but potentially in many other fields such as automotive and marine transport, as well as in building and construction," said Professor Michele Meo, who led the study, in a Phys.org report. 

"We managed to produce such an extremely low density by using a liquid combination of graphene oxide and a polymer, which are formed with whipped air bubbles and freeze-casted," said Meo in the report. "On a very basic level, the technique can be compared with whipping egg whites to create meringues — it's solid but contains a lot of air, so there is no weight or efficiency penalty to achieve big improvements in comfort and noise."

Sustainable upgrades to transportation present opportunities to tackle noise pollution

The researchers' next focus will involve collaborations with aerospace firms, to execute tests on the new material as a functioning sound insulator for real-life jet engines. But the material might also work for and in helicopters and car engines, respectively. Most crucially, the engineers at Bath believe the aerogel might see use in jet aircraft within 18 months.

This is especially relevant because, as the major nations of the world explore new and sustainable solutions to established industries like air- and ground-based transportation to reduce and eventually eliminate carbon emissions, engineers and officials have an opportunity to make additional adjustments to the machines that keep the world turning. Noise pollution doesn't exactly threaten the habitability of Earth, but it is harmful to human ears, to say nothing of the way it masks the subtler sounds of nature, which can affect the mental health and conventional behavior of not only humans, but animals, too. This isn't a "mute" button for the roar of jet engines, but cutting substantial decibels from incoming or outgoing air traffic could make society a (slightly) nicer place to live.