Have you ever tried to use an old, dry rubber band only to have it snap when you start to stretch it? Rubber bands and other stretchy materials such as adhesives tend to have problems with being both stiff enough to bounce back to their original shape after stretching and twisting, while also stretchy enough to resist breaking. Megan Valentine and Emmanouela Filippidi, both scientists at the University of California Santa Barbara, have created a material that fits both of these requirements. Their inspiration? Mussels.
Mussels are living creatures that spend their lives stuck on hard surfaces in the water, bearing crashing waves and tough conditions. In order to avoid getting swept away by waves or pried off rocks by predators, mussels produce a strong, sticky plaque that acts like a naturally-produced glue. Valentine and Filippidi studied the characteristics of this sticky plaque, and used what they observed to create a new material that is 100- to 1,000-times stronger and tougher than previous materials of its kind.
This new material contains a network of charged iron ions that are attracted to each other like magnets. Just like if you pull two magnets apart, if this material somehow breaks the two attracted ends will pull themselves back together to “heal” the break. Although this material probably won’t be replacing our old rubber bands anytime soon, it could be used to build flexible, self-healing parts for robots and other machines.