Metal-carbon nanotube composite nanoelectromechanical torsional resonators

Metallic based nanoelectromechanical systems (NEMS) resonator structures are of interest due to higher optical reflectivity, ductility, and conductivity compared to insulator- and semiconductor- based NEMS structures. We present NEMS torsional resonator structures fabricated from aluminum-carbon nanotube (CNT) and palladium-CNT composites. Metal and metal-CNT NEMS structures are released from III-V based substrates. The resonators are electrostatically driven and are detected at room temperatures under moderate vacuum conditions using optical modulation techniques. We note significant differences in the resonant frequencies (f$_{0})$ and the quality factors (Q) between metal and metal-CNT NEMS torsional resonators. Aluminum based structures with paddle dimensions of $\sim $5 micron x $\sim $5 micron, with support beams of $\sim $1 micron x $\sim $3 micron, show a fundamental resonant frequency corresponding to translational mode of 1.7 MHz with Q of 20, while Al-CNT based structures of same dimensions show f$_{0}$ of 3 MHz and Q of 50, as a typical example. We will further discuss the effects on the mechanical properties of metallic NEMS torsional resonators due to addition of CNT. {\dag}parkyd@phya.snu.ac.kr