aerogel
noun
aero·gel
ˈer-ō-ˌjel 
plural aerogels
: a light, highly porous solid formed by replacement of liquid in a gel (see gel entry 1 sense 1) with a gas so that the resulting solid is the same size as the original
By extracting the fluid from a wet gel under pressure and at a high temperature he was able to produce extremely light materials with porosities as high as 98 percent. Kistler called the solids aerogels.—
Jochen Fricke
Jochen FrickeSilica aerogel is so light that engineers sometimes call it "solid smoke." This low weight combined with excellent sound, thermal and electrical insulating properties would make aerogel ideal for a host of consumer products, were it not so expensive to produce.—Popular Mechanics
Popular MechanicsExamples of aerogel in a Sentence
Recent Examples on the Web
Her high jewelry collections employ not just the legacy building blocks of gold and diamonds, but challenge convention with unexpected materials and techniques — real flower petals or aerogel, a material developed by NASA made of 99.8 percent air and silica, for example.
—Thomas Waller, Footwear News, 11 Oct. 2025
Some desiccants are solid, others are liquid but the newest — hydrogels or aerogels — are spongy.
—Laura Paddison, CNN Money, 6 Sep. 2025
This is why Shen and his team decided to create a photothermal aerogel.
—Elizabeth Rayne, ArsTechnica, 26 July 2025
The latest proof of concept experiment builds on earlier work by Wordsworth’s team, which showed that silica aerogels could replicate Earth’s greenhouse effect to support life in cold, low-pressure environments.
—Sharmila Kuthunur, Space.com, 20 July 2025
Others are experimenting with new polymer aerogel materials based on penguin feathers that could have applications for building insulation and climate control, showing the wide variety of applications that can be based on one particularly specialized group of birds.
—Ian Rose, Smithsonian Magazine, 10 June 2025
The limits of the technology An aerogel does not prevent a fire in the first place, but if a lithium ion cell wrapped with this material ignites, the aerogel keeps the fire from spreading too far.
—Ari Daniel, NPR, 9 Dec. 2024
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Thomas Waller, Footwear News, 11 Oct. 2025
Some desiccants are solid, others are liquid but the newest — hydrogels or aerogels — are spongy.
—Laura Paddison, CNN Money, 6 Sep. 2025
This is why Shen and his team decided to create a photothermal aerogel.
—Elizabeth Rayne, ArsTechnica, 26 July 2025
The latest proof of concept experiment builds on earlier work by Wordsworth’s team, which showed that silica aerogels could replicate Earth’s greenhouse effect to support life in cold, low-pressure environments.
—Sharmila Kuthunur, Space.com, 20 July 2025
Others are experimenting with new polymer aerogel materials based on penguin feathers that could have applications for building insulation and climate control, showing the wide variety of applications that can be based on one particularly specialized group of birds.
—Ian Rose, Smithsonian Magazine, 10 June 2025
The limits of the technology An aerogel does not prevent a fire in the first place, but if a lithium ion cell wrapped with this material ignites, the aerogel keeps the fire from spreading too far.
—Ari Daniel, NPR, 9 Dec. 2024
Cite this Entry
“Aerogel.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/aerogel. Accessed 31 Oct. 2025.
Copy CitationMedical Definition
aerogel
noun
aero·gel
ˈa(-ə)r-ō-ˌjel, ˈe(-ə)r-
: a highly porous solid formed by replacement of liquid in a gel with a gas so that there is little shrinkage
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