A new monolithically integrated multi-functional MEMS neural probe for optical stimulation and drug delivery

We present a monolithically integrated multi-functional MEMS neural probe by integrating both an embedded microfluidic channel for drug delivery and a SU-8 optical waveguide for optical stimulation. In this work, we used a controlled glass reflow process to form an embedded glass layer which serves as both the cover for the microfluidic channel and the cladding layer for the optical waveguide. Using this simple fabrication process, we achieved a compact structure integrated with multiple stimulation modalities. Using our multifunctional neural probe, we demonstrated successful in vivo experiments by optically and chemically activating neurons and recording neural spike signals from individual neurons with a high SNR.