From Knowable Magazine, May 3:
Bend it. Stretch it. Use it to conduct electricity. Researchers are exploring a range of applications that harness the element’s unusual properties.
Every time you sit down with your phone in your back pocket, you’re reminded of a fundamental truth: Human bodies are soft and flexible. Electronics aren’t.
But soon there may be devices that can stretch, bend and even repair themselves when they’re damaged. By harnessing the unusual properties of a liquid metal called gallium, materials scientists aim to create a new generation of flexible devices for virtual reality interfaces, medical monitors, motion-sensing devices and more.
The goal is to take the functionality of electronics and make them softer, says Michael Dickey, a chemical engineer at North Carolina State University. “I mean, the body and other natural systems have figured out how to do it. So surely, we can do it.”
Bendable electronics can also be made with conventional metals. But solid metal can fatigue and break, and the more that’s added to a soft material, the more inflexible the material becomes. Liquid metals don’t have that problem, Dickey says — they can be bent, stretched and twisted with little or no damage.
Flexibility turns out to be just one of gallium’s useful properties. Since it’s a metal, it conducts heat and electricity easily. Unlike the better-known liquid metal mercury, it has low toxicity, and low vapor pressure, so it doesn’t evaporate easily.
Gallium flows about as easily as water. But in air it also quickly forms a stiff outer oxide layer, allowing it to be easily formed into semisolid shapes. The surface tension, which is 10 times that of water, can even be varied by submerging the liquid metal in salt water and applying a voltage....
....MUCH MORE
