The crux of nanotechnology is the problem of self-assembly, getting uncooperative atoms to link and align themselves precisely. We know it can be done, of course: life persists by turning molecules into complex biological machinery. How fitting, then, that one of today's most creative materials scientists, Angela Belcher of the Massachusetts Institute of Technology, has turned to nature for assistance. Belcher has pioneered the use of custom-evolved viruses in synthesizing nanoscale wires and arrays, fusing different research disciplines into something uniquely her own.

Belcher's goal is to harness living things as factories for assembling materials made from any of the elements of the periodic table. Her greatest success has come from the M13 bacteriophage, a long, tubular virus six nanometers wide. She engineered a version of the virus that latched onto quantum dots, tiny specks of semiconductor with desirable electromagnetic properties. By suspending the virus particles, she could make them line up, an effective means of creating finely spaced layers of quantum dots that are separated by layers of virus.

More recently, she customized M13 to stud its length with metal particles such as cobalt oxide and gold, yielding metal nanowires that could be assembled into high energy-density electrodes. Those could be incorporated, for example, into lightweight, thin-film batteries that can be easily molded to fit any space. Belcher co-founded Cambrios Technologies in Mountain View, Calif., to turn some of these demonstrations into commercial devices such as flexible, touch-sensitive screens and light-emitting diodes. In her work, DNA shows its worth as more than just the code of life.