Abstract
We previously reported high-density retinal prosthesis chips with arrays (from 64 to 4,096 pixels) of electrodes 10 μm in diameter and 30 μm in pitch using a 180 nm CMOS Image Sensor technology. Small electrodes typically face large impedance that might limit their total electrical output capability. To verify the in vitro efficacy of these high-density retinal prosthesis chips when used in sub-retinal excitation of RGC’s, we directly programmed these chips to generate biphasic current with amplitude up to +-50 μA, which will still allow operating a large array within the temperature-rise limitation.