3D printing has come a long way since it was first invented in 1983. When most of us think of 3D printers, we probably think of design applications and making “cool” things like musical instruments, iPhone cases, lights, printed fabrics, sculptures, tactile maps, and more. These days, 3D printing is also used for practical purposes in dozens of industries: aerospace, architecture, automotive, consumer goods, the defense industry, healthcare, and many more. Speaking of practicality, scientists at Brunel University London have developed a flexible, wearable battery that can be implanted into a plastic wristband using 3D printing technology.

What’s so great about this, you might wonder? Scientists at Brunel’s Cleaner Electronics Research Group say the silicone wristband will be able to charge your smartphone, smartwatch, electric car, or other device. Here’s how the technology works, according to a post on the Brunel University website: “The printer squirts stacks of silicone, glue and gel electrolyte pastes like a layer cake, to make what looks like a clear festival wristband. Sandwiched inside is a supercapacitor, which stores energy like a battery, but on its surface and without chemical reactions.” Milad Areir, PhD candidate and Library Team Member at Brunel, said the standard way to produce a supercapacitor is through screen printing, but that method is limited in that it doesn’t allow printing the frame of the supercapacitor on silicone. Other methods of making flexible supercapacitators are expensive and require different machines to print different parts. As Areir pointed out, “This is the first time a flexible supercapacitor including all its components has been produced by 3D printing.” Bringing it all together into one process with one machine will save time and make the wristband more economical to produce. The project’s researchers say it may soon be simple for anybody to print their own battery using an open-source printer connected by USB to a syringe driver and a motor to print the paste layers.

We depend on portable power for so many things these days: cell phones, smart watches, laptops, and even cars. This new technology would make wearable power sources more efficient and less costly, and charging devices more convenient. You could potentially use the supercapacitator wristband to charge your phone, laptop, or electric car until you have access to a standard charger. If you’re a “digital nomad” or other person eager to be less tethered to one locale for a specific length of time, the supercapacitator wristband could offer that freedom.