Unique effects of nanoscale conductive channel in electrochemical metallization memristors

Electrochemical metallization (ECM) memristors, with their advantages of high ON/OFF ratio, fast switching speeds, and low power consumption, have shown broad prospects in emerging applications such as neuromorphic computing, low-power logic computing, and artificial intelligence hardware. To fully realize the potential of ECM memristors, it is necessary to gain a deep understanding of the complexity of ion migration and redox reactions associated with resistive switching at the nanoscale. This review first systematically elucidates the resistive switching mechanism of ECM memristors, then focuses on discussing various novel physical effects emerging at the nanoscale, including the nanobattery effect, quantized conductance effect, diffusion effect, photo-induced resistive switching effect, and bio-voltage effect. A further review of the latest application advancements of these effects in cutting-edge fields such as artificial synapses, bioelectronic interfaces, in-memory computing, and neuromorphic perception. Finally, we explored the key challenges and potential opportunities facing ECM memristors in their future development, aiming to lay the groundwork for future neuromorphic computing research.