Fabrication of microtip electrode array integrated with self-aligned reference electrode

This paper presents a novel microtip-based electrode array with the reference electrode around tips. A microelectromechanical systems process for a microtip electrode array has been developed using DRIE and RIE combination process. The conductive microtip with high aspect ratio, small apex radius and the height of tens of micron scale is insulated except the tip ends. The tips are closely surrounded by the self-aligned reference electrode. The whole process was completed with a single photography mask. The fabricated microtip-based electrode array was successfully verified with the cyclic voltammetry measurements and characterized with the measurement of photosynthetic reaction of chlorella cell using microtip electrode array.