Thermoreversible In Situ Adaptive Biogel for Conformal Electrophysiological Interfaces with Long‐Term Robustness

ABSTRACT Robust skin‐electronic interfaces are essential for continuous epidermal electrophysiological monitoring, enabling real‐time tracking of physiological states and early detection of abnormalities. An ideal skin‐integrated interface should simultaneously provide adaptive conformability, robust adhesion, and long‐term stability. However, interfacial state mismatch arises from the conflict between the adaptive state required for intimate skin contact and the durable state needed for stable long‐term operation, making it exceedingly difficult to reconcile these attributes within a single interface design. Here, we report an in situ adaptive biogel that, enabled by thermoreversible liquid‐to‐gel transition of gelatin and synergistic interactions imparted by an ionic medium, rapidly establishes a skin interface with conformal contact, robust adhesion (7.06 N cm −1 ), and month‐long stability. These properties endow the interface with low‐impedance coupling, motion‐artifact suppression, and sustained functional reliability, supporting acquisition of multiple electrophysiological signals, continuous high‐fidelity electrocardiogram monitoring during 24 h of daily activities, and electrocardiogram recordings during a 30‐day evaluation with a signal‐to‐noise ratio of 21.41 ± 2.34 dB. Furthermore, a soft chest patch integrating the biogel enables synchronous electrocardiogram and respiration monitoring for dynamic cardiorespiratory analysis and assessment of apnea‐like respiratory interruptions. This work establishes a general strategy for engineering robust skin‐conformal biointerfaces for long‐term wearable bioelectronics.