Skin is a material with astonishing capabilities: the flexible, waterproof layer constantly regenerates itself, heals itself after scratches and cuts, and, through its nerves, conducts electricity, relaying the sense of touch to the brain. Engineers have long been trying to come up with a synthetic polymer that does all those things, and does them under standard conditions rather than the carefully calibrated set-up of a lab. Now engineers have created a polymer with a combination of skin's most elusive attributes that no polymer had achieved before: This new material, reported in Nature Nanotechnology
, can conduct electricity and, when it is sliced open with a razor, can heal itself at room temperature. The material can come back together thanks to the hydrogen bonds
, which break and reform easily and reversibly, connecting its molecules. Due to the addition of nickel particles, it can also conduct electricity. The researchers found that after the material was cut open, it regained 90 percent of its electrical conductivity within 15 seconds. What's more, the material's electrical resistance changes in response to pressure---giving this synthetic skin what is, essentially, a sense of touch. The material may eventually be used to make touch-sensitive prosthetic limbs. Meanwhile, the resilient, conductive material should aid in the development of better on-skin electronic devices
, such as wearable heart-rate monitors.
Photo courtesy of L.A. Cicero/Stanford News Service