A team at the University of Colorado Boulder has earned a Guinness World Record for the most transparent material ever created.

The lightweight, gel-like material made mostly of air is 97% to 99% transparent compared to glass, which is about 92% transparent.

“It’s exciting,” CU Boulder Professor Ivan Smalyukh said. “We have been excited the most when we measured these properties but now we are, of course, sharing this excitement, and it’s nice to be re-excited when we see other people being excited about the properties we achieved.”

The material Smalyukh and his team created is an aerogel, which is a porous, lightweight material created by replacing the liquid component of the gel with a gas. The aerogel created by CU Boulder is made up of roughly 99% air and one percent solid volume with cellulose fibers.

The project was originally developed to improve window insulation and was supported by the Department of Energy. The idea is to use the aerogel to insulate and prevent heat loss, increasing the energy efficiency of a building and reducing costs.

“Aerogels are well-known super-insulating materials. The reason it’s called usually ‘solid air’ is it’s air captured in a very light way in a solid network,” research faculty Taewoo Lee said, adding, “The problem is it’s usually not transparent. So that’s why we are really focusing on how to make it clear like a glass so we can apply it on the window insulation.”

Smalyukh said these types of materials can be used to improve energy efficiency.

“It’s important because we don’t think of buildings as primary energy consumers,” he said. “But in fact, 40% of all generated energy is somehow related to the use in buildings and a lot of the energy that goes into heating and cooling is directly linked to windows.”

One of the properties of aerogel is it’s a great thermal insulator and heat can’t pass through it.

“You can take a piece of aerogel on the top of your hand and if you use a flamethrower it will not burn you and you will not even feel the heat,” research faculty Amit Bhardwaj said. “It’s that insulated.”

Research faculty Eldho Abraham said it’s an amazing material that can have many applications anywhere insulation is needed.

“This material is going to save the energy loss of the buildings,” Abraham said, adding, “This is going to be a big solution for the energy crisis, too.”

The team submitted the record to Guinness in 2019 but it wasn’t finalized or released until the patent for the material and related research publications were accepted in the years following.

Moving forward, Smalyukh hopes these types of materials can become commercial products and help address some of the challenges of climate change.

“We can make more insulated windows that would be less bulky,” he said. “And in the ideal world, once it can become a commercial product, we hopefully can make a big impact on this problem.”