Development of a microfluidic drug delivery neural prosthesis using a wide bandgap semiconductor waveguide structure

We have developed a microfluidic retinal prosthesis, using wide bandgap optical wavelength semiconductor thin film waveguides, to facilitate spatial and quantitative photactivation of "caged" neurotransmitter to microfluidic channels. Novel waveguide materials and micromachining technology are necessary to fabricate 360 nanometer capable waveguides for the microfluidic device. Single crystal wide bandgap semiconductor thin films are grown on sapphire by plasma source molecular beam epitaxy (PSMBE). 248 nanometer KrF Excimer laser micromachining technology is employed to micro-fabricate wave-guiding channels and microfluidic structures. A waveguide that allows for spatial and temporal drug delivery within the retina was fabricated. In addition, there is a need for a waveguide structure that may be used in physiological drug delivery systems. A device that may deliver ultraviolet light in precise intensities and to selective areas of a microfluidic implant without direct ultraviolet exposure to the biological cells is needed in retinal and cortical implants. Results of a prototype microfluidic waveguide system will be presented.