MEMS-based Material Testing Systems

In the early 1990s, Iijima (1991) discovered a onedimensional (1D) nanostructure, the carbon nanotube (CNT), which sparked an entirely new avenue within nanoscience and nanotechnology. Nanowires (NWs) (Cui and Lieber 2001), nanorods (Li and Alivisatos 2003), nanotubes (Wang and Li 2003), and nanobelts (Pan et al. 2001) of various materials have been successfully synthesized shortly afterwards. These 1D nanostructures demonstrate novel mechanical (Yu et al. 2000), electronic (Wildoer et al. 1998), and optical properties (Duan et al. 2003). Potential applications for these structures range from nanoelectromechanical systems (NEMSs) (Fennimore et al. 2003) to nanoelectronics (Cui et al. 2001) to nanophotonics (Law et al. 2004). A large number of NEMS devices based on nanostructures have been realized. Fennimore et al. (2003) reported a CNT-based rotational motor (Fig. 1(a)). Kim and Lieber (1999) reported CNT-based nanotweezers (Fig. 1(b)). Multiwalled carbon nanotubes (MWCNTs) actuated by electrostatic force were used as the tweezers’ arms. NTs and NWs have been demonstrated as building blocks in logic circuits (Bachtold et al. 2001, Huang et al. 2001). In addition, they have been used as highly