Fabrication and measurements of high aspect ratio conductive microtip array with localized ultra-micro electrode at the tip end

This paper presents a fabrication and electrochemical characterization of an array of high aspect ratio conductive microtips with localized ultra-micro electrodes (UME) at the tip ends. The proposed microtip was designed to be inserted into the cytosolic space of a cell for the intracellular applications such as metabolic activity sensors and photosynthetic fuel cells. In order to be applied to these applications, the microtip structure with the localized UME was fabricated to achieve the high aspect ratio, small apex radius and the height of tens of micron scale. To fabricate the localized UME, the conductive layer on the microtip surface was revealed only at the tip end while the rest of the conductive layer was insulated electrically.