Skin-interfaced colorimetric microfluidic devices for on-demand sweat analysis

Abstract

Abstract As sweat biomarker levels are continuously changing over metabolism and daily activities, pathological and physiological processes can be dynamically analyzed by wearable devices. The colorimetric skin-interfaced microfluidic devices that do not have external circuit modules exhibit enhanced deformability with a small footprint. However, it is difficult to achieve sampling over time and self-feedback for closed-loop systems. This review summarizes recent advances in microfluidic valves for biofluid management and chrono-sampling, as well as active triggers in microfluidics self-feedback. After enumerating the current limitations in temporal resolution and reliability, we further point out a few potential feasible strategies for future developments.