Wireless, optoelectronic, multimodal skin sensor for simultaneous monitoring of mechanical stress and vascular responses

Prolonged mechanical loading and subsequent vascular ischemia drive the development of severe pressure injuries. Effective prevention of irreversible tissue damage requires monitoring both multiaxial mechanical forces and physiological erythema. However, conventional diagnostic tools remain limited by rigid architectures, single parameter detection, and subjective visual assessments. Here, a wireless, battery free optoelectronic multimodal sensor platform provides an integrated framework for tracking posture dependent mechanical loading and localized erythema. The soft, skin conformable device uses geometric light modulation within an isolated optical cavity to quantify normal pressure and biaxial shear stresses. To resolve complex mechanical environments, a deep neural network regression model decouples simultaneous tri-axial forces, Fx, Fy, and Fz, at the skin interface. Concurrently, a dual wavelength optical reflectance mechanism quantifies skin erythema by capturing subtle variations in hemoglobin absorption. Opaque elastomeric encapsulation shields the internal optics, supporting stable optical measurements under varying ambient illumination and skin conditions. System level integration via near field communication enables untethered operation across a multiplexed sensor network. On-body evaluations in a simulated clinical bed setting demonstrate the ability of the platform to dynamically map posture-dependent biomechanical loading and localized vascular responses, providing a technological basis for future studies on data-driven monitoring of the mechanical and vascular factors associated with pressure-injury risk. Pressure injuries arise from sustained mechanical loading and reduced blood flow, but current tools cannot objectively track both together. Cho et al. built a soft, wireless, battery-free, optoelectronic sensor that simultaneously maps three-axis stress and redness on the body.