Photovoltaic organic interface for neuronal stimulation in the near-infrared

Organic materials, such as conjugated polymers, are attractive building blocks for bioelectronic interfaces. In particular, organic semiconductors show excellent performance in light-mediated excitation and silencing of neuronal cells and tissues. However, the main challenges of these organic photovoltaic interfaces compared to inorganic prostheses are the limited adhesion of conjugated polymers in aqueous environments and the exploitation of materials responsive in the visible spectrum. Here, we show a photovoltaic organic interface optimized for neuronal stimulation in the near-infrared spectrum. We adjusted the organic materials by chemical modification in order to improve the adhesion in an aqueous environment and to modulate the photoelectrical stimulation efficiency. As proof-of-principle, we tested this interface on explanted degenerated mice retinas, thus providing results on the efficiency and reliability of the device as an implant for neural stimulation.