aero·​gel ˈer-ō-ˌjel How to pronounce aerogel (audio)
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
Silica 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

Examples of aerogel in a Sentence

Recent Examples on the Web The tattoos are composed of two inks—a zinc oxide ink containing embedded nanowires atop a graphene aerogel conductive ink. IEEE Spectrum, 12 June 2023 The researchers noted that enough visible light can pass through the aerogel layer to allow for photosynthesis, and suggested aerogel shields could protect crops and other photosynthetic life with minimal subsequent intervention. Charles Choi, Discover Magazine, 15 July 2019 Ergen says there is also some aerogel in the ink containing the nanowires, though at a lower ratio than that in the lower layer, and as a result, the two inks bond on contact. IEEE Spectrum, 12 June 2023 Silica aerogel, a material with a porous, spongelike structure, was used on the Stardust spacecraft to collect dust from Comet Wild 2. ABOUT THE AUTHOR(S) Christopher Norris is emeritus professor of philosophy at Cardiff University in Wales. Christopher Norris, Scientific American, 1 Sep. 2022 This poem was inspired by my seeing, handling (very carefully) and reading about a sample of aerogel given to my wife, Valerie Randle, a materials scientist. Christopher Norris, Scientific American, 1 Sep. 2022 In November researchers showed off the lightest material ever created: a strong metal mesh about 25 percent less dense than the wispiest aerogel, a foamlike material that was the old record holder. Jennifer Berglund, Discover Magazine, 28 Mar. 2012 This is surprisingly similar to the stardust@home task of searching for tracks of stardust in successive layers of aerogel. Citizen Science Salon, Discover Magazine, 1 Oct. 2016 In one experiment the researchers described an obscure synthetic material called an aerogel (actually developed in the 1930s) and told people that it had been invented either 15 years before or 15 years after their birth date. Alison Gopnik, WSJ, 29 Sep. 2022 See More

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'aerogel.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History

First Known Use

1923, in the meaning defined above

Time Traveler
The first known use of aerogel was in 1923

Dictionary Entries Near aerogel

Cite this Entry

“Aerogel.” Dictionary, Merriam-Webster, Accessed 1 Oct. 2023.

Kids Definition


: a light highly porous solid formed by replacement of liquid in a gel with a gas so that the resulting solid is the same size as the original

Medical Definition


: 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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