μLEDs for optogenetics

Abstract: Optogenetics is unfolding new ways for us to study the nervous system and could one day be a standard approach to treat neurological diseases like epilepsy. To selectively study the effects on a subcellular level, microscopic light sources are needed. Nanostructure, light-emitting diodes (LEDs) can realize this criteria but processing to connect and protect them is necessary before any fruitful optogenetic tests can be conducted. In this work, micron sized, III-nitride, LED light sources were created using microfabrication techniques such as lithography, etching and thin film deposition. Experimental biointegration and passivation schemes were then used to build a prototype optogenetic device for stimulation of primary neurons grown [i]in vitro[/i] onto the device, in close proximity to the light emitters. Favorable electrical and optical characteristics were obtained for the individual nanostructure LEDs, lighting up brightly at a wavelength around 470 nm. However, larger devices revealed process related and uniformity challenges to overcome. Additionally, the biointegration design would prove too complex and in need of further improvement. This effort, while not outputting a fully functioning device, has contributed to development of the utilized nanostructure LED technology so that we may see more of it in the future.