A component for use in a medical circuit, e.g. a mask or conduit, the component comprising a first region that, in use, contacts liquid, a second region that is distinct from the first region, and a microstructured surface in communication with the first region and the second region configured, in use, to wick liquid from the first region to the second region, wherein the microstructured surface comprises generally inverse-trapezoid-shaped structures, each including a first ridge and a second ridge having similar dimensions that project from the surface and defining a first channel therebetween.