When they say “economic circular“: a group of researchers from QUT (Queensland University of Technology) has turned human hair cut from a Brisbane hairdresser in flexible screens which could be used in future smart devices. Scholars have come up with it a two-step process, which provides for the breakage of hair and heated to 240 ° C, to transform small strands of hair into carbon “nanodot”or rather small uniform points with a magnitude of one millionth of a millimeter.
The research, published in the journal Advanced Materials, represents the first example of transformation of human hair discarded after cutting into highly luminescent carbon nanomaterials from which to obtain flexible devices capable of emitting light. The nanodots, subjected to the two-step process, were then made evenly dispersed on a polymer, on which they have assembled themselves forming “nano islands”, useful for preserving the emissivity.
The “nano islands” have been used as an active layer in an OLED device (organic light-emitting diode) capable of illuminating blue with a modest voltage, equivalent to about two or three AA batteries. “Waste is a big deal,” said associate professor Prashant Sonar.
Carbon nanodots produced by human hair they are not bright enough to be used for TVs but “they could be used in some applications such as smart packaging where a small light source is required, for example in road signs or medical devices, thanks to the non-toxicity of the material”, added the professor.
A concrete example would be one smart milk bottle, with a built-in sensor inside that provides a real-time update on milk expiration, with information displayed on a screen outside. The choice to use hair and not something else to extract carbon points is due to the fact that it is a natural source of carbon and nitrogen, key elements for obtaining particles that emit light. Another element was to prevent them from ending up in landfills.
Human hair is composed of proteins (amino acid polymers) such as keratin, which decomposes with controlled heating. The material that remains after this step it has both carbon and nitrogen in its molecular structure, which confers favorable electronic properties.
“We have shown that it works with human hair. Now we are interested in whether the same results can be obtained with animal hair“said Professor Sonar.” Maybe we could produce flexible OLEDs using small strands of sheep’s wool or dog hair from pet grooming salons. “