Telescoping Self-Aligned Metal-Catalyzed Carbon Nanotube Piezoresistors As Strain Gauges

Multi-walled carbon nanotube (MWCNT) bridges, grown using low-pressure metal-catalyzed chemical vapor deposition technique between silicon posts, were used as tiny piezoresistors to monitor vibration and bending/deformation of silicon cantilever beams. The weld strength of CNTs measured using atomic force microscope was larger than 100 nN/CNT and their full-scale resistance change was larger than 10⁵ Omega.The effective longitudinal piezoresistivity of these CNTs was larger than 4 times 10^-8 Pa^-1 which is larger than that of Pi₄₄ in silicon.