Micropillar fabrication based on local electrophoretic deposition using a scanning ion conductance microscope with a theta nanopipette

Abstract

We developed a novel local electrophoretic deposition technique using a scanning ion conductance microscope (SICM) with a double-barreled theta nanopipette. One channel of the nanopipette was used as a probe of the SICM function to control the pipette-substrate surface distance, and the other channel filled with Au colloidal solution was used for electrophoretic deposition. After positioning the pipette edge in the vicinity of the substrate using the SICM function, the colloidal Au nanoparticles were electrophoretically deposited on the substrate. The deposition was carried out in liquid environment, which realized reproducible fabrication by preventing the clogging of the pipette aperture from drying of the colloidal solution. By moving the pipette upward while maintaining the deposition, micropillars with submicrometer diameters were successfully fabricated. The mechanical properties of the fabricated pillar were evaluated using a commercial microcantilever by applying a loading force. The average Young’s modulus was calculated to be approximately 32 GPa.