Nanostructures Require Nanomeasurements

Extract

Nanofabrication is upon us. But engineers require measurements of physical properties of their materials in order to use them appropriately. Because the size of the object is in the nanometer scale, tiny measuring devices are required. Furthermore, there is the problem of reading these tiny devices. Zhong Lin Wang, Philippe Poncharal, and Walter de Heer at Georgia Tech have solved this problem by using the transmission electron microscope (TEM) to read off the measurements.

A special device was designed to fit inside the TEM, allowing for simultaneous visualization and manipulation of a nanostmcture. The nanostructure that Wang ef al, used was the carbon nanotube which could be clearly visualized by the TEM and has a well-defined structure. Specifically, they used multiwalled nanotubes with diameters of 5 to 50 nm and lengths of 1 to 20 μm. The device they designed for in situ microscopy was a modified specimen holder that allowed carbon nanotubes to be mounted in a conducting medium and positioned across from a counter electrode, which was a droplet of mercury or gold/ platinum balls.