Fig. 1.

a) schematic illustrations and optical images (inset) of soft, skin-mounted microfluidic systems for measuring the secretory pressure from sweat glands, at the surface of the skin. inset: photograph of a device on the skin b) perspective view illustration of a device with 12 capillary bursting valves. insets: optical images of device a twisted (left) and bent (right) state. c) perspective view illustration of a single capillary bursting valve integrated onto the skin, with a representative sweat gland. d) exploded view illustration of a device and its interface with the skin. top view illustrations of microfluidic channels partially filled with blue-dyed water for cases of a e) valve that is not yet burst and f) a valve that has burst. scale bar represents 10 mm in a and b.