Science can sometimes feel like a fairy godmother has waved a magic wand and carried out a transformation on par with turning a pumpkin into a carriage. But in this latest installment of “trash to treasure,” the end result could prove to be much more useful than a glass slipper.
Researchers from the Queensland University of Technology (QUT), Australia, have teamed up with a local barbershop to turn their hair scraps into flexible displays for use in future smart devices, including wearable devices and smart packaging.
In this “first-of-its-kind” study, published in Advanced Materials, the team “broke down” the waste human hairs before burning them at 240°C (464°F). Upon heating, the hair, made up of proteins including keratin, is broken down further, and the remaining material ends up containing both carbon and nitrogen – key elements to obtain light-emitting particles. The extracted carbon “nanodots”, measuring in at one-millionth of a millimeter, were then grouped into “nano-islands.”
Together these islands formed an active layer for an organic (ie containing carbon) light-emitting diode (OLED) device. This meant that when a small voltage was applied to the device, it lit up with a blue color. Although not bright enough to be used in television screens, the flexibility of the displays could see them have other uses.
“Waste is a big problem,” Associate Professor Prashant Sonar, chief investigator at the QUT Centre for Materials Science, said in a statement. “Human hair derived carbon dot-based organic light-emitting devices could be used for some indoor applications such as smart packaging. They could also be used where a small light source is required such as in signs or in smart bands and could be used in medical devices because of the non-toxicity of the material.”
The research has been taken even further by members of the same team. In a study published in Sustainable Materials and Technologies, they report that their hair-derived carbon nanodots responded with “high sensitivity and selectivity” to the presence of chloroform. Therefore, the material may have potential as a smart sensor to perform real-time monitoring of chloroform levels in water treatment systems.
“The creation of valuable material from human hair waste that has potential uses in both display and sensing opens up an opportunity towards a circular economy and sustainable material technology,” Sonar said.
In the future, the team also want to trial waste hair from other animals, to see whether their results can be replicated.
“We have proven it works for human hair. We’re now interested if we could get the same results from animal hair,” Sonar said. “Perhaps we could produce flexible OLEDs using small strands of wool from sheep or leftover dog hair from pet grooming salons.”
[H/T: Interesting Engineering]