In 2005, leading nanotechnology research firm Lux Research issued a report claiming that nanotechnology would be the basis for $2.6 trillion in new products and services by 2015. At the time, it was widely hailed by nanotech supporters as an indication of the field's immense potential. To critics, it was just another example of excessive hype.

Debate still rages over the validity of that figure. I was recently asked for my opinion, and here's my answer: I think $2.6 trillion is a reasonable estimate.

Start small
Earlier this spring, Wilbur Ross indicated that while nanotechnology is only enhancing $11 billion worth of textiles today, he expects that figure to increase to $120 billion by 2012. Meanwhile, BASF (NYSE:BF) has publicly indicated that it expects its new nanotechnology research and development facility to account for between $61 billion and $74 billion in new products by 2011.

Earlier this month, Cientific, another nano consulting firm -- and a tough critic of the $2.6 trillion figure -- issued a report on the future market for nanoparticle drug-delivery particles. The firm estimated the current market at $3.9 billion, growing only to $26 billion by 2012.

That's hardly pocket change, but it's still a thousand times short of $2.6 trillion. Even if one then adds in Ross' $120 billion projection for textiles, and BASF's $70 billion figure, the total barely reaches one-tenth of $2.6 trillion. Does that make Lux's estimate overinflated? Not necessarily.

The tip of the iceberg
For starters, all of those cited figures just take us through 2012. They don't address the next three years at all, and that's when things should get interesting. Even the ever-pessimistic Cientific admits that the market for nanoparticle drug delivery devices will grow to $220 billion by 2015 -- an eightfold improvement from its 2012 estimates.

More importantly, drug-delivery devices, textiles, and BASF's nanocoatings represent just the tip of the proverbial iceberg for nanotechnology-enabled products.

Hewlett-Packard (NYSE:HPQ), IBM (NYSE:IBM), and Intel (NASDAQ:INTC) have all announced nanotech breakthroughs in semiconductors just this year. As the industry continues to scale down the circuit paths of its chips to a mere 45 nanometers apart, with future goals of 32 and 22 nanometers, these firms' research in nanomaterials and carbon nanotubes will likely pay off in substantial ways.

The energy industry is also poised for immediate gains from nanotech in the coming years. Altair (NASDAQ:ALTI) and A123 Systems are currently employing nanotech advances to improve lithium-ion batteries, and the results are being actively explored by firms such as General Motors (NYSE:GM) and Pacific Gas & Electric. Meanwhile, Chevron (NYSE:CVX) and Headwaters are experimenting with nanoparticle catalysts to transform the heavy oils of the Canadian sand pits into lighter, more valuable crude oil.

Nanotech also holds great potential to radically transform the economics of solar-cell production. Harris & Harris holds equity stakes in at least two companies -- Innovalight and Nanosys -- pursuing advances in the field of thin-film solar cell production. Other firms pursuing similar advances include Nanosolar, Miasole, and Konarka.

An industry in its infancy
The list of companies and industries pursuing revolutionary nanotech advances is nearly endless. DuPont is creating new nanocoatings; Motorola is applying nanomaterials to the creation of flat-panel displays; and Ford and Boeing are investing millions in nanotech research, hoping for advances in the construction of next-generation airplanes and automobiles.

Given the depth and breadth of products that nanotech might enhance, Lux's $2.6 trillion figure sounds ever more realistic. The industry is undergoing exponential growth, a trend whose power most investors underestimate. Nanotechnology isn't quite doubling every year, but it's still making rapid progress. Come 2015, the field's overall value might surprise a great many people. If you want to take advantage of this opportunity, start familiarizing yourself with the industry now.

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Fool contributor Jack Uldrich is the author of two books on nanotechnology. He owns stock in Harris & Harris and Headwaters, both Rule Breakers picks, and Intel, a Motley Fool Inside Value selection. The Fool has a strict disclosure policy.