Geometrical Optimization and Simulation of NPDA Device for Future Use in Retinal Implant

Abstract

The focus of this research was to improve the device structure and electrode geometry of nanophotodiode array (NPDA) subretinal implant devices for retinal implants, with the aim to restore the sight of people who have lost their vision and visual acuity (VA) to better than blindness level. In light of the electronic device simulator, the authors present a design depicting the configuration of a high-efficiency NPDA device by incorporating organic nanomaterials. The present researchers’ simulated NPDA device embeds 3600 stimulating pixels (100 μm in diameter) dispersed over a 5.5-mm active radius area. By optimizing the NPDA device geometry, authors demonstrated that each pixel has the potential to produce the required electrical current and voltage for neuronal stimulation utilizing an irradiance of 12 mW/mm2. Here, the authors concentrated on increasing the efficiency of the device because the increase in efficiency will tend to result in more pixels (greater number of electrodes by reducing the electrode geometry) if the increase in a pixel increases the visual perception. Therefore, theoretically, the 100-μm Tin electrode can reinstate VA up to 20/80.This NPDA implant has the potential to reinforce vision to a level of VA that is superior to that of the vision loss level.