Multifunctional optoelectronic memristor based on CeO2/MoS2 heterojunction for advanced artificial synapses and bionic visual system with nociceptive sensing

The emerging intelligent nanodevices make the artificial visual system a reality. Memristors, as artificial synapses equipped with the advantages of high parallelism and low power consumption, hold considerable promise for developing biological visual systems. In this study, an optoelectronic memristor composed of Ag/CeO2/MoS2/ITO is proposed, which actualizes neural synapse functions such as short/long-term plasticity by adjusting electrical excitation, and short/long-term learning and memory conversion is realized with the assistance of a letter "NANO" pattern of 50 devices. Moreover, light is capable of replacing voltage to induce advanced synaptic functions including short/long-term memory and learning-forgetting-relearning. In particular, the device benefits from the ability to produce significantly distinguishable photoconductive effects for multi-wavelengths (620, 580, and 520 nm) and exhibits memory properties for different wavelengths. A human visual system that is able to sense, memory, and color recognition of the "traffic signal" image is implemented on a 7 × 7 optoelectronic memristor array constructed with multi-wavelength modulation. Finally, an artificial visual system with pain-sensing capability is presented, where the four key features of human visual nociceptors, namely "threshold", "no-adaption", "relaxation" and "nociceptive sensitization". This work provides a strategy to integrate sensing, memory, and visual pain devices for electronic eyes and humanoid robots in the future.