Wearable devices comprise several components, including plastic casings, batteries and sensors. There is a need for construction layer materials to hold all those components together, plus a skin-layer material to attach the device to the patient’s body. If that casing is not breathable, or if any of the construction layer materials are not breathable, the device developer will need an absorbent material that can draw in moisture from the skin while the device is worn. These variables affect device design and construction, so early collaboration between supply chain partners is best.