At first blush, aerogels sound high tech. But they're really the granddaddies of what we today think of as contemporary nanotech.

And now, after almost 80 years, they're finally finding what could become widespread commercial uses.

Invented by accident in 1931, an aerogel is a unique material produced when the liquid component of a gel has been replaced with gas. The result is an extremely low density solid with remarkable properties.

Specifically, an aerogel is the lightest weight solid on earth, and has the world's best insulating value.

While they've been an interesting curiosity to scientists and students in labs for decades, only in the last 5 years has anyone figured out how to make aerogels thin enough and inexpensively enough to be viable commercially.

One of the leading companies is privately-held Aspen Aerogels of Northborough, MA. While aerogels have traditionally been brittle, Aspen incorporated a fiber reinforcement to produce aerogel material in flexible blanket form of varying thicknesses, up to a quarter of an inch.

"Imagine how you make Jello. You add water to sugar and gelatin, and the sugar gels. Then you remove the water. In our case, it's not water and sugar, it's alcohol and silica," explained Aspen marketing Services manager John Williams [ed.: not the composer] to Cleantech.com.

The resulting material has pores about 10 nanometers wide. "At that size they're extremely effective cages for trapping air molecules," said Williams.

Aspen found an initial market for its super-insulating material in offshore drilling applications. Oil and natural gas in undersea reservoirs often has to transit long distances before reaching production platforms on the surface. If liquids get too cold on the way, they congeal in the line. Engineers typically solve the problem by wrapping pipes in bulky insulation and encasing them in larger outer pipes.

Aerogel-insulated pipes were found to be two to three times more effective than traditional insulation. As a result, drillers found they could reduce outer pipe sizes, which lowered the cost of steel for jobs. Installation costs were lowered, because more pipe could be loaded onto reels on ships, resulting in fewer trips to sea to complete the installation.

Now, Aspen's aerogel blankets are being positioned as insulating material in markets as diverse as outdoor wear, and in building and construction applications.

In the building market, which is where 75% of all insulation is sold, fiberglass is still the most economic way to fill large spaces, Aspen says, like the space between framing studs in a building. But there are places fiberglass falls down, according to Williams.

"There are essentially thermal short circuits from the inside walls to the outside walls at every stud. And this is particularly true in metal frame buildings. You could use our product as a thermal break, or stud cap. Our insulation material could be sandwiched between that stud and the facing material."

As effective as the miracle product is, don't expect every homebuilder to start using it everywhere quite yet.

"It will always remain a Cadillac insulation. It will never compete head to head on a cost basis with fiberglass, just because it's, frankly, a much more finicky animal to produce. And therefore more expensive," said Williams.

Aspen is introducing its material to specifying bodies in the construction industry and working to meet California building and construction codes. It is working with Oak Ridge National Laboratory in testing its materials for building applications.

Another aerogel manufacturer, Cabot, already has products used in the building industry positioned as semi-transparent windows.

Aspen employs 140 people at manufacturing facilities in Rhode Island and Massachusetts and in sales offices around the world. It is currently producing 30 million square feet of its product a year, and says it could scale production to 100 million if necessary.

Investors in Aspen Aerogels to date have included Rockport Capital, Lehman Brothers Venture Capital, and Reservoir Capital. The company says it is not seeking additional capital at this time.