A Review on Multi-Level Asymmetric Design for 2D Neuromorphic Devices

This review highlights the pivotal role of asymmetry as a core design strategy for realizing key neuromorphic functionalities by breaking symmetry across scales to induce unique physical phenomena. It systematically synthesizes asymmetric engineering at materials, structures, and device levels, with a focus on 2D materials to elaborate how their multi-level asymmetry enables tunable synaptic plasticity emulation. It addresses existing research gaps, discusses current challenges, and provides a forward-looking perspective to establish a coherent design framework for next-generation 2D material-based neuromorphic hardware.