Measuring physical and mechanical properties of individual carbon nanotubes by in situ TEM

Nanomaterials are a fundamental component of nanoscience and nanotechnology. The small size of nanostructures constrains the applications of well-established testing and measurement techniques, thus new methods and approaches must be developed for synthesis, property characterization and device fabrication. This has been the focus of our research, aiming at exploring state-of-the-art techniques for materials processing and characterization. This paper reviews our progress in using in situ transmission electron microscopy to measure the electric, mechanical and field emission properties of individual carbon nanotubes with well-defined structures. Quantum conductance was observed in defect-free nanotubes, which led to the transport of a superhigh current density at room temperature without heat dissipation. A nanobalance technique is demonstrated that can be applied to measure the mass of a tiny particle as light as 22 fg (1 f = 10(-15)). (C) 2000 Elsevier Science Ltd. All rights reserved.