Thin, soft, skin-mounted microfluidic networks for detection and analysis of targets of interest in sweat

A method for the detection of a biomarker in sweat comprising:

• providing an epidermal microfluidic device to a skin of a subject, wherein conformal contact is established thereby providing fluidic communication between said epidermal microfluidic device and said skin, said epidermal microfluidic device comprising:
• a flexible substrate comprising a first collection layer, a second collection layer and a capping layer disposed between the first collection layer and the second collection layer, wherein
• the first collection layer contains a first channel network forming at least one first collection chamber having a sweat inlet to being opened said skin and an outlet to the second collection layer, wherein said sweat inlet is operably in the fluidic communication with said skin;
• the second collection layer contains a second channel network forming a plurality of secondary collection chambers fluidically connected to the at least one first collection chamber, each of the secondary collection chambers having an inlet fluidically connected to said outlet of the at least one first collection chamber;
• the capping layer is formed to seal both the first channel network of the first collection layer and the second channel network of the second collection layer;
• and
• each of the first channel network and the second channel network is in a serpentine form;
• and
• an analyzer integrated with or fluidically connected to the at least one first collection chamber and/or the plurality of secondary collection chambers and configured to analyze said sweat for one or more biomarkers;
• collecting said sweat from said subject in said epidermal microfluidic device;
• and
• identifying or quantifying the amount of said one or more biomarkers in said sweat.