Light emitting textiles have the potential to expand the capabilities of clothing in the realms of fashion, advertising, sports and worker safety. Current approaches mostly include sewing electronic components, optical fibers and light emitting diodes directly into fabric. However, clothing made in this way suffers from rigidity and bulkiness, making it relatively uncomfortable to wear.A team of researchers from the University of Windsor.
Canada, reports a new technique for the fabrication of light-emitting textiles that deposits metal directly on the individual fibers of an ultrasheer fabricWearable electronics like smart watches and activity trackers have already broken into the mainstream, and many experts believe that smart clothing represents the next step. Smart clothing may have sensors to detect biometric data, batteries or solar cells as power sources, and LEDs to display patterns or data output.
More often than not, today’s smart clothing is made by simply stitching electronic components into the fabric. But having stiff optical fibers running through a sweater or an inflexible electrode in the sleeve of a workout shirt is less than ideal. Clothing should be comfortable, durable and washable—attributes that conflict with the vast majority of electronic parts.Instead of trying to apply conventional thin-film device-fabrication methods to fabrics, we wanted to see if we could use the intrinsic structure of the fabric as an integral part of the design,” said Tricia Carmichael, senior author and professor of surface and materials chemistry at the University of Windsor.
Carmichael and her knitted fabric manufacturers colleagues started with an ultrasheer knitted fabric made of 87% nylon and 13% spandex—pantyhose. They used electroless nickel-immersion gold metallization, a solution-based technique commonly used in printed circuit board fabrication, to deposit a gold metal film on the surface of the fibers. Scanning electron microscopy confirmed that both the nylon and spandex fibers had an approximately 100-nm thick uniform gold coating. The pantyhose material retained its softness, stretchiness and transparency.We found that the technique was a good way to integrate metal into fabrics, and that it could coat even tiny fibers with metal,” said Carmichael. “The resulting textile still feels like fabric, just shinier, and the conductivity is very good.
