Fabrication of Su-8-Based High-Aspect-Ratio Optrode Array Integrated with Reflowed Glass Lenses Using an Out-of-Plane Configuration

The proposed optrode array features an integrated structure of optrodes and reflowed glass lenses. From an optical perspective, the integration of these two structures can enhance optical efficiency because the SU-8-based optrode array is fabricated using reflowed lenses. Additionally, the geometric structure of the lens is predictable through design, and cracks can be suppressed during the thermal reflow process used to create the lens shape by utilizing plasma surface treatment. From a geometric perspective of the optrode, the advantage is that the pitch, diameter, and height within the optrode array can be freely altered. This geometric freedom allows the optrode array to be applied to experiments in various brain regions, from the brain's surface to deep brain areas. Finally, the integrated electrodes provide a biocompatible, scalable neural interface that can perform electrical recording simultaneously with optical stimulation.