Characterizing the physical properties of carbon nanotubes is limited not only by the purity of the specimen, but also by the size distribution of the nanotubes. Traditional measurements rely on scanning probe microscopy.
Using Transmission Electron Microscopy (TEM) Techniques to Measure Carbon Nanotubes
Based on transmission electron microscopy, Dr. Zhong Lin Wang and his colleagues in the School of Materials Science and Engineering at the Georgia Institute of Technology, have developed a series of unique techniques for measuring the mechanical, electrical and field emission properties of individual nanotubes. The in-situ TEM technique developed by him is not only an imaging tool that allows a direct observation of the crystal and surface structures of nanocrystals, but also an in-situ apparatus that can be effectively used to carry nano-scale measurements (Science, 283 (1999) 1513).
Viewing the Quantum Conductance of Carbon Nanotubes via Transmission Electron Devices
Using a custom-built specimen stage, the quantum conductance of a carbon nanotube has been observed in-situ in TEM, confirming the ballistic conductance and no-heat dissipation across a defect-free nanotube first published by de Heer's group (Science, 280 (1998) 1744). A nanobalance technique and a novel approach toward nanomechanics have been discovered. (Phys. Rev. Letts. 85 (2000) 622). Their discoveries have attracted a great deal attention from the media and the professional community.