In the race to make computer chips that are ever faster and ever
smaller, scientists at Harvard University have grown tiny
crystal rods of silicon and other semiconductors, then sluiced
them onto chips to form rudimentary circuits that perform basic
logic operations.  Compared with competing techniques, the
semiconductor rods, or nanowires, are easier to make and
manipulate, and they may be easier to miniaturize to the sizes
needed for superfast computer chips. ''They have a lot of
advantages in that we can control their properties quite well,''
said Dr. Charles M. Lieber, a professor of chemistry at Harvard
who led the research.  Dr. Lieber said the nanowires might also
make ''unbelievably good sensors'' for proteins, DNA and other
biological molecules. Among other things, that could aid the
development of devices to detect pathogens like anthrax.  The
findings are reported today in the journal Science.  For several
decades, the technology of carving transistor circuits into
silicon has been improved to pack