引き上げ法によるカーボンナノチューブ探針の簡易作製

Abstract

Carbon nanotubes (CNT) are just beginning to be used as probes for scanning probe microscope (SPM) systems because of the extreme high resolution that can be obtained. But processing of CNT probes have a lot of difficulties such as the need of using large equipments, long synthesizing time, low productivity and high price. A new quick and simple method for synthesizing CNT probes has been under study. In this research, a 'pulling method' is proposed and suitable synthesis conditions are investigated. This method utilizes viscosity and surface tension of solvent and electrophoresis between SPM probe and CNT dispersion liquid. The CNT can be attached to the apex of SPM probe by pulling-up process from CNT dispersion liquid. An etched SPM tungsten probe is pulled from multi wall carbon nanotube (MWNT) dispersion liquid with a bias voltage. The suitable conditions obtained are as follows: isopropyl alcohol is used as the solvent with CNT concentration of 0.05 mg/mL, bias voltage of 14 V and pulling rate of 14 μm/s. The processing time of one trial is within 1 minute and the success rate is about 70 %. It is also possible to prepare multi-connected CNT probe, single wall CNT probe and CNT probe for atomic force microscope. Therefore, our new method is suitable for mass production of CNT probes.