fig5

Figure 5. Flexible photovoltaic electrical stimulation device based on silicon photodiodes. (A) High-resolution photovoltaic retinal prosthesis system, including image projection part, photoelectric conversion part, and calibration and tracking part^[9]. Reprinted with permission. Copyright 2005, IOP Publishing; (B) Silicon photodiodes are packaged with SU-8, and columnar structures are designed to improve the biocompatibility of the device^[53]. Reprinted with permission. Copyright 2007, IOP Publishing; (C) Two different silicon photodiode arrays are designed: square and hexagonal^[54]. Reprinted with permission. Copyright 2012, Springer Nature; (D) A planar monopolar photosensitive pixel structure is designed to reduce the size to 20 μm^[58]. Reprinted with permission. Copyright 2022, Springer Nature. IR: Infrared; GCL: ganglion cell layer; INL: inner nuclear layer; CHO: choroids.