One of the challenges of nanotechnology is
finding ways to position the minuscule building blocks that make up
microscopic electronics and machines.
Researchers from the University of Minnesota have coaxed tiny particles
of gold, silver and carbon to assemble into patterns on silicon wafers
over areas as large as a square centimeter by using electrical charge
patterns to attract and position the nanoparticles.
The process, which uses the same principle as photocopying, can
eventually be used to form wires, circuits and even nanoscale devices like
transistors and lasers, according to the researchers.
The researchers were able to print 10- to 100-nanometer particles into
patterns with features as fine as 200 nanometers using a process that
started with the nanoparticles suspended in liquid. They were able to
print features as fine as 100 nanometers by directing particles towards
the charged surface using gas.
A nanometer is the span of 10 hydrogen atoms, and 100 nanometers is
1,000 times narrower than a human hair.
The process can handle many types of materials, can print patterns
quickly by using parallel print heads, and has the potential to print as
narrow as 10 nanometers, according to the researchers.
The technique is several years away from being used in practical
production processes, according to the researchers. The work appeared in
the October, 2003 issue of Nanotechnology.