Stimulation-artifact-free, High-channel-count MicroLED Optoelectrodes

Abstract:

Study of the intricate networks inside the brain requires techniques that can provide high-resolution, large-scale monitoring and manipulation capabilities. In vivoextracellular electrophysiology and genetic-engineering-assisted optical stimulation combined, or opto-electrophysiology, has proven its great potential to be one of the best tools for study of the intricate networks inside the brain. Micro-LED optoelectrodes enabled in vivoopto-electrophysiology at the highest spatial resolution to date. However, the temporal resolution and the scale of neuronal signal recording the prototype mLED optoelectrodes had been limited due to existence of stimulation artifacts and large feature sizes of integrated components.

The work presented on this dissertation focuses on realization of stimulation-artifact-free, high-channel-count mLED optoelectrodes for high-resolution, large-scale opto-electrophysiology. Two main objectives of the work are (1) elimination of stimulation artifact on mLED optoelectrodes and (2) implementation of high-density, large-scale mLED optoelectrodes. For the first objective, sources of stimulation artifacts on mLED optoelectrodes were thoroughly studied and artifact of each type was addressed with an appropriate engineering scheme. For the second objective, an advanced photolithography technique for generation of sub-micron metal patterns was utilized to enable high-density integration of the components. Results from in vitro andin vivovalidation experiments are presented.

Chair: Professor Euisik Yoon