Design and Development of Biomimetic Hydrogel Interfaces for Enhanced Bioelectrical Signal Acquisition

Every second, human skin processes over one million sensory signals while maintaining properties such as electrical conductivity, mechanical adaptability, and regenerative capability that surpass all synthetic materials. Contemporary bioelectronic devices prove inadequate when contacting skin surfaces due to poor adhesion and electrical contact issues that prevent effective sensing. Despite advancements in wearable and bioelectronic technologies, current devices face major drawbacks when interfacing with human skin, particularly in maintaining firm adhesion, conformability, and low-noise electrical signal acquisition. This research focuses on the development of a biomimetic hydrogel-based interface for bioelectronic sensing. Specifically, a hybrid hydrogel system composed of polydopamine (PDA)- doped polyacrylamide (PAM) was devised to mimic the functional characteristics of natural skin. Within this soft, hydrated matrix, various conductive and reinforcing dopants including iron oxide (Fe₃O₄) nanoparticles, graphene nanoplatelets (xGNP), and lithium chloride (LiCl) were incorporated in different combinations to tune the hydrogel’s conductivity, and mechanical integrity while strengthening bioelectrical performance and skin adhesion. The synthesized hydrogel composites were characterized using a suite of physicochemical, mechanical, and electrical tests to evaluate adhesion performance, stretchability, biocompatibility, and signal fidelity. Results demonstrated that a formulation containing all three dopants (Fe₃O₄, xGNP, and LiCl) as the best-performing composition, achieving the most favorable balance. The results show that such a biomimetic hydrogel can enable more reliable long-term biosignal monitoring in applications such as wearable health devices, biomedical diagnostics, human–machine interfaces, and soft robotics.