Wanna become a Real-Life Wolverine?
By Melissa Zhu
What do Buffy, Naruto and Wolverine have in common?
All of them have a ‘healing factor’ – the ability to recover from physical damage at a superhuman rate.
What if we told you that regular people might be able to do the same in the near future, you would probably call us ridiculous. Yet this ‘healing factor’ is no longer confined to the pages of science fiction or comic books. Researchers have, in real life, created an artificial skin that can heal itself quickly at room temperature, raising possibilities for so many other uses.
A*STAR scientist Benjamin Tee, working with a cutting-edge team at Stanford University, is primarily responsible for this innovation. For his work, Tee was recently featured on the prestigious MIT Technology Review's 35 Innovators Under 35 list.
The Science of Self-Healing
Electronic skin (‘e-skin’) is a flexible, film-like material typically made with inexpensive plastics covered with tiny micro-particles. The material created by Dr Tee is a type of e-skin made of plastic that has long chains of molecules joined by hydrogen bonds. The atoms are loosely bound, forming a weak attraction to each other.
This loose bond is crucial to the amazing self-healing property of the material, as the particles can easily break from each other when they experience mechanical damage, and just as easily re-associate afterwards. Dr Tee has fittingly compared this material to a sort of “nano velcro”.
“I cut myself accidentally once and thought: ‘Can we make an electronic skin that can heal itself just like human skin?’”
- Dr Benjamin Tee, A*STAR scientist
In a demonstration of their material, the Stanford scientists cut a thin strip with a scalpel and gently pressed it together. Within a few seconds, the e-skin regained an impressive 75% of its original strength and conductivity. Sounds like it would hold up just fine in a fight.
Sense the Footsteps of a Fly
While other scientists around the world are working on similar materials, Tee’s is probably the closest to human skin so far. Other than being able to heal by itself, the material is also flexible and can detect minute changes in pressure.
An important step in the creation of the e-skin is the addition of nickel particles to the plastic base. These lend mechanical strength to the skin, allowing it to withstand high levels of pressure despite the weakness of the hydrogen bonds. The tiny surfaces of the pieces of metal also remain rough, helping an electrical current flow from one section to the next.
It is this electrical conductivity that gives the e-skin extremely high sensitivity to pressure. Just like human skin, it can detect even slight differences in the pressure of a handshake and even register the light tickle of a fly’s gentle landing.
As a PhD student at Stanford, Tee used his e-skin to build a “smart bandage” which could detect the pulse on the radial artery when taped to the wrist. He has also experimented with using it as a non-invasive method of measure brain pressure.
If used on smartphone screens, the material could provide a more multi-dimensional sensory experience, responding to variations in pressure in addition to the location of touch. Of course, you will never have to worry about scratches again.
But the uses of Tee’s strong, self-healing and pressure-sensitive e-skin are most obvious in prosthetics and robotic skins. Artificial limbs could be made more responsive, and eventually they might even be able to communicate touch to some sort of central nervous system, reacting organically just like natural limbs.
Anyone else thinking of humanoid Cylons right now?