Microfabricated optoelectronic neural implants for optogenetics

Optogenetics is an emerging technology that allows targetable, fast control and readout of specific neural populations in complex brain circuits. The intricate and complex interactions between different neural populations require novel implantable neural interfaces that are capable of manipulating and probing targeted neurons at multiple sites and with high spatiotemporal resolution. Advanced microtechnology has offered the highest potential to meet such demands of optogenetic applications. This paper reviews our recent progress in the development of microfabricated optoelectronic neural implants that are capable of optical stimulation and electrical recording of multilevel neural activity. Utilizing microscale light-emitting diodes (μ-LEDs) as the light source, these microimplants range from a planar multichannel LED-ECoG (electrocorticogram) array to a newly developed wireless optrode array. Such multifunctional devices are demonstrated to apply temporally simultaneous optical neuromodulation and electrical neural recording in optogenetic rats.