A New Fabric for Wearable Electronics Works by Mimicking Human Tendons

The wearable electronics we've always dreamed of just got a boost thanks to technology inspired by the connective tissue that holds our bodies together. In a neat bit of biomimicry, a group of Swiss scientists have developed a type of polyurethane-based material they say is the linchpin for technological garments, and it's based off our own tendons.

It's an engineering breakthrough for a soon-to-be industry that hasn't been able to find a suitable vessel for delivering a piece of apparel to meet our expectations. We've been fed dreams of flexible smartphone screens that bend in your pocket and personal health monitoring devices fitted seamlessly into your windbreaker. We want them yesterday. But we don't have the materials we need just yet.

The biggest trick in bringing those pipedreams to fruition is creating a conductive material that is stretchy and flexible like a cotton T-shirt, and doesn't break or tear, [says Andre Studart](http://www.reuters.com/article/2012/12/11/us-science-stretchy-electronics-idUSBRE8BA0TW20121211 ), a materials scientist at the Swiss Federal Institute of Technology in Zurich and who is behind the polyurethane advancement. When scientists have tried implanting rigid microchips in flexible fabric, the result is typically a tear where the fabric meets the chip. Polyurethane, on the other hand, takes the optimal properties from rubber and plastic and provides the base material for all kinds of durables, ranging from hoses to skateboard wheels.

The material Studart's team engineered is a stretchy sheet containing pockets of stiff "islands" designed to house circuitry. The sheet is 350% stretchable–enough to compensate for the islands, which are comprised of a synthetic clay and aluminum oxide and don't stretch at all. If the circuit is stretched even one percent, it would break, Studart explained to TechNewsDaily. You can read the nitty gritty details of the material's composition in an article published in the latest edition of Nature Communications, but the basic concept is modeled on the balance between elasticity and rigidity already put to use in our own bodies.

"There are many biological materials that have these properties as well, like the way tendons link muscle to bone," Studart told Reuters. "But there are not so many examples in synthetic materials."

The collagen in our tendons is soft and stretchy (collagen lips, anyone?) and is riddled with tiny, mineral platelets that strike a dynamic balance between flexibility and stiffness that allow you to bend your bend your elbow or curl your toe without risking a tear.

At the moment, Studart's only shown the material to successfully house an LED light bulb. But the implications extend to ideas for bendable solar panels and screens that could be rolled up like a magazine. He believes the first generation of flexible electronics will be commercially available in five or 10 years, and it's a fairly realistic expectation. For example, a start-up in Massachusetts, mc10, is already working on "tools that can move with us" in the medical, consumer, commercial and military industries. If that technology proves viable, perhaps the smartphone sweatpants of your dreams aren't as far off as previously thought.