Field emission of telescoping multi-walled carbon nanotubes

Field emission of telescoping multi-walled carbon nanotubes is investigated. Local "kink"-like fluctuation of emission current is observed, which is argued to be caused by the change of the protruding length of nanotube core, i.e., the completely pulling out or saturated emission current caused shortening while pulling out of the telescoping nanotube under strong local field. In either case, this suggests the possibility of stimulating a linear motion of the core of nanotube, and serves as a base for the construction of linear nanoactuators or oscillators with the emission current as position sensing strategies.