How green is my valley...

Everybody is wondering where the nanotech equivalent of Silicon Valley will appear. Californians are banking on Silicon Valley itself; Texans are thinking maybe Austin, around the University of Texas; New Yorkers are hoping the Valley will coalesce around the Albany Institute of Nanotechnology and Applied Sciences. Build it and they will come; that is also the thinking of Virginia, which chose to locate the nanotech-oriented Institute for Advanced Learning and Research in the midst of a former tobacco field in economically depressed Danville. So far they have also lured Luna Nanoworks, a nanomaterials company, run by C-Sixty founder Stephen Wilson, presumably with the use of some serious financial incentives. Still it seems to me that the original SiliconValley was an emergent phenomenon. By definition, something that is emergent cannot be predicted from initial conditions. The shape of the requisite seed crystal and the concentration of critical components cannot be known beforehand.

Think nanotech, and my home state, Tennessee, does not immediately spring to mind. Not that we don’t have some wonderful stuff here. Beautiful streams and lakes. Deer and wild turkey in abundance. A vibrant music industry around Nashville. But high tech industry so far has been absent, despite some natural advantages, like a central location on the shipping routes, and the presence of some fine research institutions like Oak Ridge National Laboratory and Vanderbilt University. So I was pleasantly surprised to hear about the TNano2 conference (http://www.technologycouncil.com/news.php?viewStory=926) put on by Vanderbilt on October 6th in Nashville. Among those giving presentations were Nanosys CEO Larry Bock, and venture capitalist Clint Bybee, co-founder of Arch Ventures. Sarah Whisenant, from Sun Micro, was scheduled but had to cancel at the last minute. I promise to talk more about Bock in the next post. The subject of the day, however, is diamonds. Jim Davidson (www.vuse.vanderbilt.edu/~jld/persinfo.htm ), Professor of Electrical Engineering at Vanderbilt gave a talk at TNano2 that was all about these enchanting rocks.

Diamonds are nanotechnologist’s best friend…

So, I’m sure you’ve heard about Drexlerian dream of diamondoid mechanosynthesis. Drexler’s little robots may never materialize, but he and his followers got one thing right: diamond is an excellent nanomaterial. The standard way to make diamonds is to depend on Ma Nature as she expends tons of pressure on a coal deposit for a billion years or so. But that’s not the only way to do it. These days diamonds can be “cultured” through the application of a mere 58,000 atmospheres of pressure at about 1300 degrees Centigrade. A Florida based company called Gemesis will sell you gem-quality cultured diamonds in white, yellow or blue.

Huge quantities of heat and pressure is a brute force way of doing something. This an anathema to the discerning nanotechnologist like Jim Davidson; he uses a more subtle method called chemical vapor deposition (CVD). In this process, a diamond chip is enlarged by carbon gas, one atom at a time (without the need for an assembler) under suitable conditions of temperature and pressure. CVD is not exactly new; it has been used for years to make diamond coatings and small industrial diamonds. And then, of course, there is the revolutionary diamond-coated frying pan; a 12.5 inch pan can now be obtained for only $99.00 (http://www.swiss.diamond.com/ ). No more will we have to deal with scratched up Teflon.

The CVD process has been recently improved. Apollo Diamond, a startup that is the brainchild of Bryant Linares, hopes to make a 2 carat CVD gem quality diamond this year using CVD. De Beers, with its near monopoly on mined diamonds, is not amused. Linares is more interested in use of diamonds in electronics than the flashy ice, however.Jim Davidson, too doesn’t care a lot about diamond gems; he is into more useful stuff, like diamond-based MEMS sensors, resistors, capacitors, diodes and cold cathodes. Like its relative, the carbon nanotube, diamond has intrinsic properties that are hard to beat, like electrical conductivity, heat conductivity and unmatched hardness and durability. Diamonds can also be doped to turn them into semiconductors; CVD diamond has even been proposed as a very heat conductive, durable replacement for silicon in making chips.

Davidson also mentioned my choice as the killer app for CVD diamonds--the thermoelectric generator. Diamonds are coated onto a surface within a vacuum device. An anode is placed on the opposite side. Heat up the diamond side and electrons are released from the pointy ends of the diamonds and collected at the anode. Electricity is generated directly from heat with no moving parts. With gas and heating oil going through the roof, pricewise, and the earth overheating, what could be a better idea than a device that turns heat into electrical energy? This diamond-studded thermoelectric generator could be the basis of a co-generation device or a solar cell.