They are made of silicon - chemically identical to glass - but are 3,000 times less dense due to air pockets that can take up to 600 pounds per square inch of pressure before collapsing and losing insulation capability. They are about three times as effective as present insulation materials of equivalent thickness, or, said another way, three times thinner for the same insulation ability.

Their use in clothing, especially for extreme conditions, is obvious but when used for building insulation they have mad R factors and significantly reduce energy consumption. But there is a considerable amount of whingeing about their cost. It is claimed that a combination of savings in construction costs and subsequent energy use makes them cost effective.

I want aerogel insoles for my winter boots.