How to grow wires and tiny plates

MIT News
July 14, 2011

Researchers at MIT have found a way to grow submicroscopic wires in water with great precision, using a method that makes it possible to produce entire electronic devices through a liquid-based process.

The team demonstrated the technique, called hydrothermal synthesis, by producing a functional light-emitting diode (LED) array made of zinc oxide nanowires in a microfluidic channel. They were able to do so on a lab bench under relatively benign conditions: essentially using a syringe to push solution through a capillary tube one-tenth of a millimeter wide, without expensive semiconductor manufacturing processes and facilities.

Unlike larger structures, with nanomaterials — those with dimensions measured in nanometers, or billionths of a meter — differences in shape can lead to dramatic differences in behavior. “For nanostructures, there’s a coupling between the geometry and the electrical and optical properties,” explains Brian Chow PhD ’08, co-author of a paper describing the results that was published July 10 in the journal Nature Materials. “Being able to rationally tune the geometry is very powerful because you can, in turn, tune the functional properties.” The system Chow and his colleagues developed can precisely control the aspect ratio (the ratio of length to width) of the nanowires to produce anything from flat plates to long, thin wires.
To read more click here...