Engineers Create Battery-Free Wearables From Cloth That Can Be Washed

The popularity of wearable electronics has increased dramatically in recent years, particularly in the form of smartwatches. While these devices are typically water-resistant, they're certainly not washable as you would wash clothing. Engineers at Purdue University have developed a new method that transforms existing cloth items into battery-free wearables resistant to laundry.

Smart clothes are powered wirelessly using a flexible, silk-based coil sewn into the textile. The breakthrough could mean clothing in the future becomes smart. Smart cloth would outperform conventional passive garments thanks to the miniaturized electric circuits and sensors embedded inside. The circuits and sensors would allow seamless communication between the phone, computer, car, and other machines.

Engineers say smart clothing could make users more productive, check their health status, and possibly call for help in the event of an accident. One challenge building material of this type in the past has been that the fabrication of smart clothing is challenging because clothes need to be periodically washed, and electronics are typically incompatible with water.

To overcome that hurdle, engineers developed a new spray/sewing method to transform traditional cloth into battery-free wearables that can be cleaned in the washing machine. The team spray-coated the smart cloth with a highly hydrophobic molecule rendering them repellent to water, oil, and mud. The team says the smart clothes are nearly impossible to stain and can be used underwater and washed in conventional washing machines without damaging the electronic components integrated inside them.

Often wearable electronic garments have reduced breathability, making them uncomfortable for long-term wear. However, the ultrathin coating process for the new smart clothes makes them as flexible, stretchable, and breathable as conventional cotton shirts. The wearable electronic clothing Purdue engineers created needs no batteries. They are powered by harvesting energy from Wi-Fi or radio waves in the environment. The team's breakthroughs are patent pending.