The goal, when adhering to skin, is to hold the device in place until it is time to remove it and to not damage the skin, either during wear or at the time of removal. Using methods developed for determining the surface energy of plastics and other materials, the surface energy for human skin has been measured in the low twenties [dynes/cm] – in other words, skin is as difficult to stick to as untreated polyolefins or even fluoropolymers.