TAILIEUCHUNG - Nano and Microelectromechanical Systems P3

Carbon Nanotubes and Nanodevices Carbon nanotubes, discovered in 1991, are molecular structures which consist of graphene cylinders closed at either end with caps containing pentagonal rings. Carbon nanotubes are produced by vaporizing carbon graphite with an electric arc under an inert atmosphere. The carbon molecules organize a perfect network of hexagonal graphite rolled up onto itself to form a hollow tube. Buckytubes are extremely strong and flexible and can be single- or multi-walled. The standard arc-evaporation method produces only multilayered tubes, and the single-layer uniform nanotubes (constant diameter) were synthesis only a couple years ago. One can fill nanotubes with. | CHAPTER 3 STRUCTURAL DESIGN MODELING AND SIMULATION . NANO- AND MICROELECTROMECHANICAL SYSTEMS . Carbon Nanotubes and Nanodevices Carbon nanotubes discovered in 1991 are molecular structures which consist of graphene cylinders closed at either end with caps containing pentagonal rings. Carbon nanotubes are produced by vaporizing carbon graphite with an electric arc under an inert atmosphere. The carbon molecules organize a perfect network of hexagonal graphite rolled up onto itself to form a hollow tube. Buckytubes are extremely strong and flexible and can be single- or multi-walled. The standard arc-evaporation method produces only multilayered tubes and the single-layer uniform nanotubes constant diameter were synthesis only a couple years ago. One can fill nanotubes with any media including biological molecules. The carbon nanotubes can be conducting or insulating medium depending upon their structure. A single-walled carbon nanotube one atom thick which consists of carbon molecules is illustrated in Figure . The application of these nanotubes formed with a few carbon atoms in diameter provides the possibility to fabricate devices on an atomic and molecular scale. The diameter of nanotube is 100000 times less that the diameter of the sawing needle. The carbon nanotubes which are much stronger than steel wire are the perfect conductor better than silver and have thermal conductivity better than diamond. The carbon nanotubes manufactured using the carbon vapor technology and carbon atoms bond together forming the pattern. Single-wall carbon nanotubes are manufactured using laser vaporization arc technology vapor growth as well as other methods. Figure . illustrates the carbon ring with six atoms. When such a sheet rolls itself into a tube so that its edges join seamlessly together a nanotube is formed. Figure . Single-walled carbon nanotube 2001 by CRC Press LLC Figure . Single carbon nanotube ring with six atoms Carbon nanotubes which

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