Optofluidic biomolecule sensors based on a-Si:H microrings embedded in silicon-glass microchannels.

The large-scale and low-cost fabrication of high sensitivity sensors for the real-time detection of biochemicals and molecular substances opens up new opportunities in the areas of bioanalytic screening and medical diagnostics. Planar integrated photonic resonators that can be fabricated with a low footprint, in spatial and wavelength multiplexed arrangements, and that enable integration with microfluidics on the wafer scale have emerged as a promising sensing platform for these application fields. We realized an optofluidic and label-free biosensor that is based on hydrogenated amorphous silicon microring resonators embedded in silicon/glass microfluidic channels for analyte injection and biomolecule immobilization. The optofluidic sensor merits for refractive index and biomolecule sensing are evaluated by sensitivity and detection limit simulations, whereas a proof of concept is demonstrated by real-time protein immobilization experiments of functionalized resonators.

Intraocular epiretinal prosthesis to restore vision in blind humans.

Visual sensations in blind patients suffering from retinal degenerations may be restored by electrical stimulation of retinal neurons using implantable microelectrode arrays. The EPI-RET-3 project was initiated to evaluate a wireless intraocular retinal implant system for human use in terms of safety and efficiency. The implant is a remotely controlled fully intraocular prosthesis consisting of a receiver and a stimulator module. The stimulator is placed onto the retina's surface. Data and energy are transmitted via an inductive link from outside the eye to the implant. The EPI-RET-3 device was implanted into six legally blind patients with Retinitis Pigmentosa (RP) for a period of four weeks. The surgery was performed without complications. The implants were activated on days 7, 14 and 27 after implantation. All patients reported visual sensations such as dots, arcs, or lines of different colours and intensities. The required stimulation thresholds were found to be very low. Implantation of the wireless EPI-RET-3 device is safe and the system is suitable to elicit visual sensations in blind RP patients. Major problems in the design and fabrication of a prosthesis for artificial vision could be solved in this approach.