Artificial skin as heat-sensitive as pit vipers--the most sensitive heat detectors in nature--could one day help prosthetics and robot limbs detect subtle changes in temperature, a new study finds. Many research groups around the world are developing flexible electronic skin for prosthetic limbs that can help replicate the sensory capabilities of real skin. When it comes to temperature, existing flexible sensors recognize changes of less than one-tenth of a degree C, but only within temperature ranges of less than 5 degrees C. Other flexible devices can work in wider temperature ranges, but are many times less sensitive. Now scientists have developed an electronic skin that is sensitive to changes as little as one-hundredth of a degree C over a 45-degree range, from 5 C to 50 C. This sensitivity is comparable to that of pit vipers such as rattlesnakes, the researchers say.