Fabrication of Microtip Electrode Array with Varying Heights for Electrical Measurement of Neural Cells

This work proposed the fabrication of microtip electrode array with varying heights for electrical measurement of neural cells at localized areas. The proposed microtip electrode array can be fabricated using MEMS processes such as DRIE (Deep Reactive Ion Etching) and RIE (Reactive Ion Etching). By adjusting the diameter of the pillar and the spacing between the pillar and the dummy, it is possible to simultaneously fabricate microtips with varying heights within the array. Furthermore, the proposed fabrication process requires only a single photolithography mask, resulting in a high alignment accuracy. The fabricated microtip electrode array selectively exposed electrode only the tip end of the microtip for electrical measurements. The electrode measurements were validated using a three-electrode electrochemical measurement.