Chaoxin Ji, Jun Yang, Xiaomei Wang, Y. Wang, Yanjing Li, Xiaoyue Liang, Jun Zhao, Cao Lian-zhong
ABSTRACT Human–machine interfaces are increasingly vital for health monitoring and human–computer interaction. However, their practical application is hindered by challenges such as material swelling, delamination, and signal distortion caused by sweat immersion and mechanical strain. This review systematically examines recent breakthroughs in multiscale design strategies for anti‐swelling hydrogels, encompassing molecular‐scale crosslinking network regulation, micro/nano‐scale confinement design, and macro‐scale device integration. Through approaches including hydrophobic modification, dynamic bond introduction, nanocomposite integration, and gradient structure fabrication, the structural integrity, consistent electromechanical performance, and biocompatibility of hydrogels in complex physiological environments have been significantly improved. The functional implementation and efficacy of these materials are explored in applications such as motion sensing, wearable rehabilitation devices, and implantable neural interfaces, highlighting their advantages in maintaining high signal‐to‐noise ratios, low impedance fluctuations, and stable long‐term adhesion under wet or mechanically dynamic conditions. Finally, this paper proposes that future research should focus on bio‐inspired intelligent structures, dynamically responsive interfaces, and heterogeneous integration technologies to advance anti‐swelling hydrogels toward clinical‐grade, highly robust human–machine interaction systems.