So a team of Northwestern University scientists turned to chemistry and developed a new method that can routinely and cheaply produce nanowires with gaps as small as five nanometers wide -- a feat that is unattainable using conventional lithographic techniques. The results will be published in the July 1 issue of the journal Science.
Carved gaps are essential to a nanowire's function, and controlling those gaps would allow scientists and engineers to design with precision devices ranging from tiny integrated circuits to gene chips and protein arrays for diagnostics and drug discovery.
"With miniaturization happening across so many fields, our existing tools -- our chisels of a sort -- can't control the shapes and spacing of these small structures," said Chad A. Mirkin, director of Northwestern's Institute for Nanotechnology, who led the research team. "Our method allows us to selectively introduce gaps into the wires. These gaps can be filled with molecules, making them components for building small electronic and photonic devices or chemical and biological sensors."
The development of sophisticated nanoelectronics, said Mirkin, depends on the ability to fabricate and functionalize electrode gaps less than 20 nanometers wide for precise electrical measurements on nanomaterials and even individual molecules. While conventional techniques can't make gaps much smaller than 20 nanometers wide, Mirkin's method, called on-wire lithography, or OWL, has been able to produce gaps as small as 2.5 nanometers wide.