A team of Stanford University chemists and engineers has created the first synthetic material that is both sensitive to touch and capable of healing itself quickly and repeatedly at room temperature. The advance could lead to smarter prosthetics or resilient personal electronics that repair themselves.Not only is our skin sensitive – sending the brain precise information about pressure and temperature – but it also heals efficiently to preserve a protective barrier against the world. Combining these two features in a single synthetic material presented an exciting challenge for Stanford University chemical engineering Professor Zhenan Bao and her team. Now, they have succeeded in making the first material that can both sense subtle pressure and heal itself when torn or cut. The researchers succeeded by combining two ingredients to get what Bao calls "the best of both worlds" – the self-healing ability of a plastic polymer and the conductivity of a metal.
The next step was to see how well the material could restore both its mechanical strength and its electrical conductivity after damage. The researchers took a thin strip of the material and cut it in half with a scalpel. After gently pressing the pieces together for a few seconds, the researchers found the material gained back 75 percent of its original strength and electrical conductivity. The material was restored close to 100 percent in about 30 minutes. What's more, the same sample could be cut repeatedly in the same place. After 50 cuts and repairs, a sample withstood bending and stretching just like the original.