Making the world’s smallest gadgets even smaller

You may not have noticed, but the smallest revolution in world history is under way. Laboratories and factories have begun to make medical sensors and computer-chip components smaller than a single blood cell or the periods on this page.

Charles Lieber, Hyman Professor of Chemistry, has been making such diminishingly small things for years. He and his colleagues at Harvard’s Department of Chemistry and Chemical Biology and the Division of Engineering and Applied Sciences have fabricated detectors for viruses and prostate cancer that measure about 10 nanometers (50 atoms) in size.

The race to the bottom of matter involves not only constructing smaller, more efficient devices but also finding better ways to make the tools needed to produce these things. In the Nov. 25, 2005 issue of the journal Science, Lieber, along with graduate students Chen Yang and Zhaohui Zhong, announced a unique way to fabricate nanodevices.

Instead of using conventional methods to make wires that connect together nanotransistors and other circuit components, this team built the components right into the wires. Rather than constructing a device that is later programmed to contain information and to perform a function, they built the information and function right into the wires.

Here’s the way Lieber puts it: “We have demonstrated the controlled synthesis of nanostructures at levels of complexity significantly beyond any work yet reported. What we have done is the most challenging synthetic problem in these structures, and one with huge potential payoffs from both the standpoint of fundamental scientific impact and producing novel devices and applications.”