Meringue-like material could help reduce aircraft noise

According to the researchers behind the material, the low-density graphene-based aerogel weighs just 2.1kg per cubic metre, making it the lightest sound insulation ever manufactured. Aircraft manufacturers could use it as insulation within aircraft engines to reduce noise by up to 16dB – reducing the 105dB roar of a jet engine taking off to a sound closer to that of a hairdryer.

The aerogel’s meringue-like structure makes it extremely light, meaning it could act as an insulator within aircraft engine nacelles, with almost no increase in overall weight, the team added. The material is being further optimised by the research team to offer improved heat dissipation, offering benefits to fuel efficiency and safety.

“This is clearly a very exciting material that experts could apply into products in several 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 of the Department of Mechanical Engineering at the university.

Meo added: “We produced 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. On a very basic level, we can compare the technique 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 enormous improvements in comfort and noise.”

Although the team’s initial focus was on working with partners in aerospace to test the material as a sound insulator in aeroplane engines, they said the material could also help create panels in helicopters or car engines. They also estimated that the aerogel could be in use within 18 months.

The researchers, from Bath’s Materials and Structures Centre (MAST), published their method for manufacturing the materials in the journal Nature Scientific Reports.