Wireless\nand Opto-Stimulated Flexible Implants: Artificial\nRetina Constructed by Ferroelectric BiFeO<sub>3</sub>‑BaTiO<sub>3</sub>/P(VDF-TrFE) Composites

The\ndegeneration of retinal photoreceptors is one of the primary\ncauses of blindness, and the implantation of retinal prostheses offers\nhope for vision restoration in individuals who are completely blind.\nFlexible bioelectronic devices present a promising avenue for the\nnext generation of retinal prostheses owing to their soft mechanical\nproperties and tissue friendliness. In this study, we developed flexible\ncomposite films of ferroelectric BiFeO<sub>3</sub>-BaTiO<sub>3</sub> (BFO-BTO) particles synthesized by the hydrothermal method and ferroelectric\npoly(vinyldene difluoride-trifluoroethylene) (P(VDF-TrFE)) polymer\nand investigated their applications in artificial retinas. Owing to\nthe coupling of the photothermal effect of BFO-BTO particles and the\npyroelectric effect of the P(VDF-TrFE) polymer, the composite films\ndemonstrate a strong photoelectric response (a maximum peak-to-peak\nphotovoltage > 80 V under blue light of 100 mW/cm<sup>2</sup>)\nin\na wide wavelength range of light (from visible to infrared) with the\ninherent flexibility and ease of preparation, making it an attractive\ncandidate for artificial retinal applications. Experimental results\nshowed that blind rats implanted with artificial retinas of the composites\ndisplay light-responsive behavior, showcasing the effectiveness of\nvision restoration. This study demonstrates a novel approach for employing\nferroelectric materials in vision restoration and offers insights\ninto future artificial retina design.