Strain‐Decoupled Serpentine Heterostructured Hydrogel Electrodes for Motion‐Artifact‐Resistant Electrophysiology

ABSTRACT Motion artifacts caused by mechanical mismatch at the skin–electrode interface remain a central barrier to reliable epidermal electrophysiology during dynamic activity. Here, we report a strain‐decoupled serpentine heterostructured hydrogel electrode (SHGE) that integrates a laser‐patterned serpentine geometry with a laminated bacterial cellulose/tannic acid supporting layer and a conductive MXene/poly(vinyl alcohol) hydrogel layer. The heterostructure provides interfacial hydrogen bonding and topological interlocking, while NaOH‐induced PVA nanocrystalline domains and the serpentine layout jointly suppress crack propagation and localize deformation away from the sensing interface. As a result, the SHGE exhibits a fracture energy of 23.4 kJ m −2 , suppressed resistance drift under 0°–120° bending, stable electrical output over 50 000 bending cycles, and strain‐insensitive operation up to 70% deformation. During dynamic electromyography and electrocardiography recordings, the SHGE reduces motion‐induced baseline fluctuation and maintains higher signal‐to‐noise ratios than commercial Ag/AgCl electrodes across multi‐day and outdoor exercise protocols. When integrated with a wireless acquisition module and a machine‐learning classifier, the high‐fidelity signals enable classification of eight representative human motions with an overall accuracy above 90% under the tested data‐splitting protocol. The same heterostructure strategy enhances fracture resistance across multiple polymer matrices, indicating a general design route for deformation‐resistant hydrogel bio‐interfaces.