Speaker
Description
Continuous glucose monitoring is critical for diabetes management. Hydrogel-based microneedle glucose biosensors have recently emerged as a promising approach for minimally invasive, real-time monitoring by sampling interstitial fluid in the upper skin layers. Because microneedles penetrate only shallow tissue depths, the measured signal reflects a spatially dependent proxy of vascular glucose concentration. Here we present a mathematical model describing glucose transport in layered human skin coupled with a hydrogel microneedle. The model consists of coupled partial and ordinary differential equations describing transport across tissue layers and the microneedle, together with surface reaction dynamics at the sensing interface. The framework incorporates key mechanisms including diffusion, interstitial transport, blood–tissue exchange, and cellular glucose uptake. Simulations reproduce experimentally observed delays in interstitial glucose dynamics across skin layers and enable quantification of key sensor performance metrics such as response time. By exploring design parameters including microneedle geometry, hydrogel diffusivity, and surface reaction kinetics, the model identifies transport limitations and design trade-offs governing sensor dynamics. The framework also highlights how inter-individual heterogeneity in skin structure and transport properties influences sensor performance.
