The smart skin, which in photos appears to drape a prosthetic hand like a see-through glove, is made of a soft polymer known as elastomer, and contains pressure, temperature and humidity sensors and stretchable electrodes that stimulate the existing nerves. The researchers were able to demonstrate how the skin could sense pressure from catching a ball as well as the temperature of a cup of hot or cold water. It could tell wet from dry, and the skin's heat sensors responded when it touched a baby doll warmed to body temperature.