A team of South Korean researchers have created a synthetic equivalent to human skin that is able to detect pressure as well as stresses and forces being applied to it, such as pinching. This artificial skin was derived from the intermolecular forces between “nanohairs” and can not only be easily manufactured, but done so cheaply.
Here at Inhabitat, we are fascinated by the idea of artificial skin due to its life-changing potential to help those with disfiguring injures. Previously, we have looked at the University of Mississippi’s attempts, which has seen the creation of a skin that is capable of repairing itself! However, the Korean team from Seoul National University have been challenging themselves to create a skin made with in-built sensors. While much progress has been made, the team’s research has not been free from issue — there are severe design constraints as the sensors are highly complex to fabricate. There is also the problem that the skin needs to be very thick if it is to wrap around toes, fingers and other body parts that may need ‘repairing’.
The Korean skin system works on the principle of piezoresistance, where charges are generated from applied mechanical stress. The skin design uses two slightly separated thin layers of a flexible polymer – polymethylsiloxane (PDMS) – each of which are covered with a very thin layer of platinum to make them conduct electricity. But what makes their artificial skin design so unique is the use of platinum-covered “nanohairs” which cover the inner surface of both layers of polymer. The “nanohairs” cause the two layers of polymer to be drawn together like a kind of molecular Velcro, allowing the platinum to generate an electrical connection. In fact, all of this makes the artificial skin even more sensitive than human skin!
It was nature that inspired the skin’s design – a beetle in fact. Kahp-Yang Suh, the team leader, says they looked at the wing-locking mechanism of beetles for their design. “A beetle folds its wings at rest by mechanically interlocking two microhair arrays called microtrichia on the outer wing and inner body.”
Speaking about his team’s creation and its economical production, Kahp-Yang Suh added: “It’s very easy to replicate this hairy structure using a standard soft-lithography process. You can easily replicate from a single silicon master by a process called replica moulding, which is well established in our field.”
The team’s research has been published in the latest issue of Nature Materials.
Images: Lee J Haywood and MBSLAB at Seoul National University