Science: Skin is flexible, durable, and sensitive to touch, which is transmitted by electrical signals. A team led by Zhenan Bao of Stanford University combined thin, flexible “epidermal electronics” with self-healing polymers to create a flexible conductive material that can restore its mechanical and electrical properties after being cut. Self-healing polymers are plastics that are able to reattach themselves after being cut. However, most such materials are not particularly conductive. Bao’s team solved that problem by adding nickel atoms to the polymer and letting electrons pass between the metal ions. To demonstrate the effectiveness of the new polymer, they used a scalpel to slice the material and then pressed the pieces together for 15 seconds. The material’s conductivity was 98% of what it had been prior to the separation, and the process could be repeated many times. There are some questions as to whether the material heals as well if it is twisted or torn apart instead of sliced, which only minimally deforms the material. Bao says her team’s next project will be attempting to make the material more elastic to make it even more skin-like.