Fig. 3: Electronics-free sweat control and feedback technologies in colorimetric microfluidic devices.
From: Skin-interfaced colorimetric microfluidic devices for on-demand sweat analysis
Enhanced structure stability with (a) rigid microchannels embedded in a soft elastomer89 (scale bar: 5 mm) and (b) check valves in microchannels to prevent reagent backflow47. Active trigger with (c) finger-actuated pumps for on-demand sweat analysis92 (scale bar: 5 mm), (d) strain-actuated pinch valve for microchannels reset93, and (e) manually activated button for negative pressure suction reset94 (scale bar: 1 cm). f Reuse with replenishment of sweatainer for multiple colorimetric analysis95. g Sweat-triggered chemesthetic feedback (C.A. = chemesthetic agent)93.
