Aerogel is a synthetic porous ultralight material derived from a gel, in which the liquid component of the gel has been replaced with a gas. The result is a solid with extremely low density and low thermal conductivity. Aerogels are derived from a variety of gel precursors, including silica, chromia, tin oxide, and carbon.
Some of the emerging trends in aerogel include the use of aerogel for insulation, the use of aerogel for sound absorption, and the use of aerogel for fuel cells.