Pico-Newton order force measurement using a calibrated carbon nanotube probe by electromechanical resonance

Force measurement with pico-Newton (pN) order resolution using a carbon nanotube (CNT) probe, which is calibrated by the electromechanical resonance is presented. Based on the theoretical analysis, a CNT is suitable material for the sensitive force measurement. A CNT probe is constructed by attaching a CNT to the tip of the commercially available atomic force microscope (AFM) cantilever or tungsten needle probe by the electron-beam-induced deposition (EBID) though the nanorobotic manipulators inside a field-emission scanning electron microscope (FE-SEM). In order to attach a CNT quickly and correctly, CNTs are dispersed in ethanol by ultrasonic waves for several hours and oriented by electrophoresis. The elastic moduli of CNTs are calibrated from electromechanical resonance frequency by applied electrostatic forces. We measured pico-Newton order contact forces with a CNT probe, which is constructed with nanorobotic manipulators, by measuring deformation of a CNT probe from FE-SEM images.