Electrical-Light Coordinately Modulated Synaptic Memristor Based on Ti3C2 MXene for Near-Infrared Artificial Vision Applications.

Emerging optoelectronic memristive devices with high parallelism and low-power consumption have made neuromorphic computing hardware a tangible reality. The coordination of conductivity regulation through both electrical and light signals is pivotal for advancing the development of synaptic memristors with brainlike functionalities. Here, an artificial visual synapse is presented with the Ti3C2 MXene memristor which demonstrates not only the nonvolatile memory effect (Set/Reset: 0.58/-0.55 V; Retention: >103 s) and sustained multistage conductivity, but also facile modulation of both electrical- and light-stimulated synaptic behaviors. By adjusting the stimulus parameters, the Ti3C2 MXene enables the realization of biosynaptic excitatory postsynaptic current, sustained conductivity, stable long-term facilitation/depression, paired pulse facilitation, spiking-timing-dependent plasticity, and experiential learning. Particularly, benefiting from the distinguishable photoconductive and memory effects of multiple near-infrared intensities (7-13 mW/cm2), potential applications in visual nociceptive perception ("threshold", "noadaption", "relaxation") and imaging (e.g., "Superman" cartoon character) in infrared environments are well achieved in such Ti3C2 MXene memristors. These results hold significant implications for the future advancement of integrated optoelectronic sensing, memory, nociception, and imaging systems.

Multifunctional black phosphorus pressure sensors with bending angle monitoring and direction recognition characteristics.

Flexible pressure sensors, an important class of intelligent sensing devices, are widely explored in body-motion and medical health monitoring, artificial intelligence and human-machine interaction. As a unique layered nanomaterial, black phosphorus (BP) has excellent electrical, mechanical, and flexible characteristics, which make it a promising candidate for fabricating high-performance pressure sensors. Herein, hierarchically structured BP-based pressure sensors were constructed. The sensors exhibit high sensitivity, stability and a wide sensing range and respond to various human motions including finger pressure, swallowing, and wrist bending. The sensors can identify different handwriting processes with featured signals. In particular, benefiting from the unique structure of loose-dense layers, the sensors show a distinctive response to bending angles and directions, revealing a characteristic of direction recognition. This feature facilitates the sensors to monitor human motions. The sensors have been successfully powered by a home-made Cu2ZnSn(S,Se)4 thin-film solar cell, which demonstrates the sustainability, flexibility and low power consumption of integrated devices. This work offers a strategy to construct hierarchically structured pressure/strain sensors with direction recognition and provides further insights into manufacturing portable sensing devices for realistic and innovative applications.