Multilayer Adhesive Fluid Collection Articles Including Capillary Channels

The present disclosure provides articles including an adhesive layer; a film layer bonded to the adhesive layer having a microstructured surface including numerous capillary channels; and a cover layer disposed on the capillary channels and attached to the adhesive layer. The adhesive layer is hydrophobic and includes an aperture for fluid (e.g., sweat) collection from a skin surface. The film layer also includes an aperture that overlaps the adhesive layer aperture to direct collected fluid to the capillary channels of the microstructured surface, which have a hydrophilic surface. Optionally at least one indicator chemistry can be present in the channels to facilitate optical (e.g., visual) determination of total fluid volume and/or concentration of at least one analyte in the fluid as a function of time.