Highly elastic conductive hydrogel bandage with a Laplace's law-based framework for quantitative interface pressure monitoring

Engineered conductive hydrogel bandage enables quantitative and interpretable wound pressure monitoring. • PEDOT network supports stable electromechanical transduction with ultralow hysteresis. • Laplace-guided analysis establishes a direct linkage between electrical signals and interfacial pressure. • High elasticity, rapid recovery, and long-term durability support reliable wearable sensing. Quantitative control of interface pressure is essential for effective chronic wound treatment, yet remains challenging due to the lack of reliable real-time sensing strategies with direct physical interpretability. Here, we establish a physics-guided conductive hydrogel bandage (CHB) integrating a Laplace-based analytical framework to enable quantitative mapping between electrical signals and interfacial pressure. The CHB comprises a poly(vinyl alcohol)-reinforced polyacrylamide network, where dynamic hydrogen bonds between hydroxyl and amide groups dissociate to dissipate energy and reform upon release, preserving elasticity and structural integrity over 5000 cycles. A continuous poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) conductive pathway is further incorporated to provide stable signal transduction with low hysteresis (<5%) and a near-linear response (gauge factor (GF) = 1.4) at 350% strain. By integrating the calibrated resistance–strain and strain–force relationships, strain-dependent bandage width, and wrapping radius into Laplace's law, the CHB converts relative resistance changes into quantitative interface pressure, yielding close agreement between predicted pressures and measurements from a commercial pressure sensor (regression slope = 1.05). Beyond conventional empirical sensing, our approach provides a physically interpretable and potentially generalizable framework for quantitative pressure analysis in flexible wearable sensing. Together with its asymmetric adhesion, favorable in vitro cytocompatibility, skin compatibility, and suitable water vapor permeability, the system offers a promising platform for quantitative wound pressure monitoring to support more consistent compression management of chronic wounds. A highly elastic conductive hydrogel bandage converts deformation-induced resistance changes into quantitative interface pressure through a Laplace-based model. Under conformal wrapping on cylindrical surfaces, mechanical strain generates stable resistance variations (ΔR/R₀), which are correlated with pressure by considering bandage tension and curvature. The calculated pressure agrees well with experimental measurements, demonstrating a physically interpretable strategy for pressure quantification in wearable bandage systems. Download: Download high-res image (127KB) Download: Download full-size image