ABSTRACT

We use a self-detecting cantilever (NPX1CTP003, SII) as a force sensor.2 The system has a three-dimensional inertialdriven actuator (UNISOKU Co., Ltd.) as a sample stage. Thus, the base plate can be set on the conventional stage of a scanning electron microscope (SEM) (S-3000N, Hitachi, base pressure of 2 × 10−3 Pa), instead of the normal sample holder. The sample stage is controlled by a computer via an A/D, D/A-compatible board. SEM images can be recorded as a movie using a video recorder. Because the resolution of A/D is 10 mV, the maximum resolution of the force sensor is approximately 0.1 nN. The fabrication of a multiwalled carbon nanotube (MWCNT)-attached probe is performed in the SEM chamber. First, using the chemically etched metal probe that is xed on the actuator, an MWCNT is pulled out from as-prepared MWCNT powder on the opposite support. Then, the MWCNT on the metal probe is moved toward the tip of a cantilever using an actuator. When an electron beam is irradiated around the contact junction between the MWCNT and the cantilever tip, the hydrocarbon is piled there and it works as a glue. Finally, when the metal probe is quickly withdrawn, the MWCNT is attached parallel to the cantilever. The handling of an MWCNT has been developed through improvements in the instruments described in previous reports.6,7 Once the MWCNT has been sufciently approached to the substrate surface using a coarse motion, the control was changed from coarse motion to ne motion. The adhesion and exfoliation experiments were repeated using ne motion.