The future for smart clothing is brighter than ever and will be accelerated by advances in sensors and in smart textiles. The smart clothes integrated with miniaturized electronic circuits and sensors will allow you to seamlessly communicate with your phone, computer, car, and other machines. However, the fabrication of this smart clothing is quite challenging, as clothes need to be periodically washed and electronics despise water.
Now, a group of Purdue University engineers has developed a new spray/sewing method to transform any conventional cloth items into battery-free wearables that can be cleaned in the washing machine. These smart clothes are powered wirelessly through a flexible, silk-based coil sewn on the textile.
“By spray-coating smart clothes with highly hydrophobic molecules, we are able to render them repellent to water, oil and mud,” said Ramses Martinez, an assistant professor in Purdue’s School of Industrial Engineering. “These smart clothes are almost impossible to stain and can be used underwater and washed in conventional washing machines without damaging the electronic components sewn on their surface.“
Unlike typical waterproof garments, Purdue’s smart clothes remain as flexible, stretchable, and breathable as conventional cotton T-shirts – thanks to their ultra-thin coating. Most importantly, these smart clothes do not require batteries for powering. By simply harvesting energy from Wi-Fi or radio waves in the environment, the clothes can power the circuitry sewn on the textile. This enables the safe wireless powering of wearable electronics via magnetic resonance coupling without compromising the user’s comfort.
The team used this textile in the fingertips of a wireless voltage detection glove that illuminates when the wearer’s hand approaches a live cable. The other example is a miniaturized cardiac monitoring system sewn on a washable sweatband capable of monitoring the wearer’s health status.
“The wearable devices, powered by ubiquitous Wi-Fi signals, will make us not only think of clothing as just a garment that keeps us warm but also as wearable tools designed to help us in our daily life, monitor our health, and protect us from accidents,” Martinez said.
The new technology can be fabricated in conventional, large-scale sewing facilities, paving the way toward the rapid development and commercialization of machine-washable and battery-free smart clothing and reusable wearable electrophysiological sensors.