Of all our human organs, skin is arguably one of the most abused — yet it’s also arguably the most reliable. It protects everything inside us, helping us avoid harm by sensing obstacles in our way, making sure we stay hydrated, and ensuring we keep ourselves at the right temperature. It constantly replenishes itself, sloughing off former layers that we’ve either burned or dried out or scraped or ignored, while new ones grow in their places. 

Many of skin’s properties would be useful in other applications — like helping people with artificial limbs regain some of what they’ve lost. And an electronic skin, or at least some tactile sensory ability, could help machines understand the delicate differences in force that are required to grip an apple, a hand or a piece of steel.