A rotary-actuated compression sensor for real-time biomechanical assessment of human skin

Human skin displays complex viscoelastic behavior arising from the interplay of collagen, elastin, and dermal ground substances, yet existing suction- and indentation-based devices provide limited physiological relevance and insufficient temporal resolution to characterize dynamic mechanical responses. We developed a novel contact-based elasticity device that applies controlled mechanical micro-compression using a rotary actuator and quantifies deformation through time-resolved electrical resistance sensing. A fully automated algorithm segments the resulting time-series into repeated base–peak–trough cycles and extracts multi-dimensional biomechanical descriptors, including deformation amplitude, loading slope, snap-back velocity, recovery time, and energy-based metrics. Validation with PDMS standards confirmed that five of six parameters robustly distinguished materials of different stiffness, demonstrating high sensitivity across a broad elasticity range. In individual measurements revealed clear lateral asymmetry within a single individual: the right cheek exhibited greater deformation and steeper loading slopes, whereas the left cheek showed faster recovery kinetics. A total of 250 participants aged 16–80 years were enrolled, including 218 female and 32 male participants, five viscoelastic parameters exhibited significant positive correlations with age (r = 0.16–0.33), revealing age-dependent degradation patterns that were not detectable in raw data. These findings demonstrate that integrating controlled compression with high-frequency resistance sensing enables detailed, physiologically relevant quantification of skin mechanics beyond the capabilities of traditional suction devices. The device algorithm system offers a robust platform for dermatologic evaluation, cosmetic efficacy testing, population-level aging research, and next-generation personalized skin-profiling technologies. • Rotary-actuated device measures skin mechanics via high-frequency resistance sensing • Automated algorithm extracts multi-cycle deformation and recovery features • PDMS and silicone phantoms validate five mechanical parameters across stiffness range • In vivo tests reveal cheek asymmetry in stiffness and viscoelastic recovery behavior • IQR filtering reduces 250 subjects to 199 high-quality datasets, strengthening age trends