YORKTOWN HEIGHTS, N.Y. — Gaze into the electron microscope display in Frances Ross' laboratory here and it is possible to persuade yourself that Ross, a 21st-century materials scientist, is actually a farmer in some Lilliputian silicon world.
Ross, an IBM researcher, is growing a crop of mushroom-shaped silicon nanowires that may one day become a basic building block for a new kind of electronics. Nanowires are one of the most promising examples of a transformation now taking place in the material sciences as researchers push to create the next generation of switching devices smaller, faster and more powerful than today's transistors.
The reason many computer scientists are pursuing this goal is that the shrinking of the transistor has approached fundamental physical limits. Sooner or later, new materials and new manufacturing processes will be necessary to keep making computer technology cheaper.
In the long term, new switches might be based on magnetic, quantum or even nanomechanical switching principles. One possibility would be to use changes in the spin of an individual electron to represent a 1 or a 0.
"There is a branching tree, and there are many possible paths we might take," said Michael C. Mayberry, an Intel Corp. vice president and the director of the company's component research program.
Back at IBM, Ross acknowledged that significant challenges remain in perfecting nanowire technology. The mushroom-shaped wires in her laboratory now look a little like bonsai trees. To offer the kind of switching performances chip-makers require, the researchers must learn to make them so that their surfaces are perfectly regular. Moreover, techniques must be developed to make them behave like semiconductors.
IBM is also exploring higher-risk ideas like "DNA origami," a process developed by Paul W.K. Rothemund, a computer scientist at the California Institute of Technology.
The technique involves creating arbitrary two- and three-dimensional shapes by controlling the folding of a long single strand of viral DNA with multiple smaller "staple" strands. One can form everything from nanometer-scale triangles and squares to elaborate shapes: smiley faces, a rough map of North America.