Soon, Gadgets Will Repair Themselves When Broken; Magnetic Ink Will Help Them Self-Heal

A sports bra that monitors your workout. A suit that lets you swap business cards digitally. A beanie hat that tracks your newborn’s vitals. Smart garments like this hint at a future coming up fast. Most wearable electronics today are expensive and complicated to make, with multiple moving parts. One option for making cheaper components is to print devices using a process with special;, electrically functional inks. The promise of printed electronics is low-cost, flexible devices – including batteries, sensors and wearable circuits that can be incorporated into smart clothing. But the multibillion dollar industry has a major downfall: Printed electronics are fragile. Researchers are now working on a solution: ink that includes magnetic particles. If a fabric or device printed with this magnetic ink breaks, the particles would attract one another and close the gap. In a paper published in Science Advances on 3 November, researcher said that their self-healing ink could repair multiple cuts up to three millimeters long in just 50 milliseconds. Smart clothes typically include sensors that have been woven into or clipped onto the fabrics. For the most part these sensors aren’t printed, which can make them more costly and rigid. Researchers wanted to make wearable devices that were more skin like. Just like the human skin is stretchable and self-healing, they wanted to impart a self-healing ability to printed electronics. The ink that researchers created includes ground neodymium magnets that are found in hard drives and refrigerator magnets. They pulverized these magnets into microscopic particles and incorporated them into the ink. Traditionally, attempts to create self-healing materials have relied on a chemical reaction called polymerization. While this has the benefit of melding broken fragments back together via chemical bonds (as opposed to magnetic attraction holding two pieces together), self-healing polymer systems require external inputs like heat, cannot seal large cracks and can take anywhere from hours to days to repair themselves. Using magnetic particles for self-healing does not require adding heat, light or other chemicals. Magnetic ink is also cheap: researchers estimated that $10 worth of ink materials can yield hundreds of small devices. The next steps are to determine the optimal ratios of ink ingredients for specific applications. These inks could make their way into everything from solar panels to implantable medical devices.