Shining the Light on Nanofabrication

With its name, it's probably no surprise that San Diego-based Nanogen http://www.nanogen.com has quickly amassed a portfolio of patents covering nanoassembly. "We were very lucky because we have incredibly early priority on this," says Nanogen cofounder Michael Heller, of a trio of now-patented nanofabrication methods.

In January, Patent Watch highlighted patent 6,652,808 for a method that allows for the self-assembly of DNA particles on preformed motherboard substrates.¹ Like this and the other previous patents, the most recently awarded piece of intellectual property (6,706,473) uses electric fields to guide the assembly of nanoparticles. What makes it different is that it doesn't require a preformed motherboard substrate.

Instead, it requires a blank, "chemically stabilized semiconductor photodiode or photoconductor surface" coated with streptavidin-agarose, and light beams to activate areas on the substrate. "Wherever you make a spot, an electric field develops," says Heller, a professor at the University of California, San Diego. "Where ...