Fabrication and measurement of microtip electrode array with self-aligned integrated dual conductive electrodes

摘要

In this paper, we present a novel microtip electrode array with integrated dual conductive electrodes on a silicon-based microtip structure. The first electrode is exposed at the tip ends forming a localized conical ultra-micro electrode (UME). The tips are insulated except the tip ends and closely surrounded by the self-aligned second electrode, which can be used as a reference or counter electrode in the measurements requiring two isolated electrodes. The microtip structure with high aspect ratio, small apex radius and the height of tens of micron scale was realized with a micromachining technique using a combination process of reactive ion etching (RIE). The whole process was completed with a single photolithography mask. The detailed fabrication process and analysis of the results are presented. In addition, the fabricated microtip-based electrode array was characterized with the cyclic voltammetry measurements and successfully verified with the measurement of photosynthetic reaction of chlorella cell.