NEMS-on-a-tip: Force sensors based on electromechanical coupling of individual multi-walled carbon nanotubes

This paper introduces the concept of nanoelectromechanical systems on a tip (NEMS-on-a-tip). As an example, force sensors based on the interlayer electromechanical coupling of individual multi-walled carbon nanotubes (MWNT) are designed with various configurations. The devices are fabricated and characterized using nanorobotic manipulation inside a scanning electron microscope (SEM). Experimental results verify that the resistance of MWNTs is highly sensitive to applied mechanical load. A further performance analysis also indicates that a force sensor configuration in which two electrodes connect to the inner and outermost shells, respectively, provides the highest sensitivity and resolution (∼1nN) in the presence of lateral forces.