Human skin is soft and stretchy and has millions of nerve endings that sense heat and touch. This makes it a superb instrument for detecting and responding to the outside world. Engineers have been working to reproduce these abilities in a synthetic version for the past 40 years, but such attempts have always fallen fall short of the versatility and adaptability of living skin. Now, however, new research is adding more abilities and complexities to bring this field closer to its ultimate goal: an electronic skin, or e-skin, with uses ranging from covering robots to sticking wearable devices onto humans.