A Neuron-Readable Artificial Photoreceptor Composed of Photodeformable Liquid Crystal Polymers and Piezoelectric Materials

Artificial photoreceptors are extensively developed to help the patients with serious eye diseases by converting light into electric signals. However, the existing systems still suffer from poor output signals, restricting signal transduction to cells. Here, a neuron-readable artificial photoreceptor with significant voltage output is constructed by using photodeformable liquid crystal polymers (LCPs) and polyvinylidene fluoride trifluoroethylene (P(VDF-TrFE)). The significant voltage output originates from light-stress-electricity conversion, where the photo-induced stress is attributed to the free volume expansion of the photodeformable LCPs and subsequently converts them into strong electric signals by the P(VDF-TrFE) layer. The photo-induced open-circuit voltage reaches up to 0.79 +/- 0.02 V, which is, to the knowledge, 19 times higher than the maximum voltage (0.04 V) that has been reported to date. Hence, such artificial photoreceptor successfully transduces photo-induced electric signals to cells and tissues, communicates with the neurons, and triggers spiking activities in blind retinas. Besides, visual image recognition is demonstrated in a pixelated matrix by analyzing electric signals of each unit. This artificial photoreceptor opens new opportunities for the combination of the photodeformability and piezoelectricity, providing an avenue to develop neuron-readable artificial retinas and implantable sensors.