The fashion industry is increasingly the focus of ways to reduce waste. And now textile engineers are researching a wool like product that has fascinating properties.
The material is made using keratin, a fibrous protein found in hair, nails and shells. The researchers extracted the keratin from leftover Agora wool used in textile manufacturing.
Kit Parker, the Tarr Family Professor of Bioengineering and Applied Physics at SEAS ( Harvard John A. Paulson School of Engineering and Applied Sciences ), said:
“We have shown that not only can we recycle wool but we can build things out of the recycled wool that have never been imagined before.
“The implications for the sustainability of natural resources are clear. With recycled keratin protein, we can do just as much, or more, than what has been done by shearing animals to date and, in doing so, reduce the environmental impact of the textile and fashion industry.”
Luca Cera, a postdoctoral fellow at SEAS, explained:
“”The organization of the alpha helix and the connective chemical bonds give the material both strength and shape memory.”
When a fibre is stretched or exposed to a particular stimulus, the spring-like structures uncoil, and the bonds realign to form stable beta-sheets. The fibre remains in that position until it is triggered to coil back into its original shape.
For example, one keratin sheet was folded into a complex origami star as its permanent shape. Once the memory was set, the researchers dunked the star in water, where it unfolded and became malleable. From there, they rolled the sheet into a tight tube. Once dry, the sheet was locked in as a fully stable and functional tube. To reverse the process, they put the tube back into water, where it unrolled and folded back into an origami star.
“This two-step process of 3D printing the material and then setting its permanent shapes allows for the fabrication of really complex shapes with structural features down to the micron level.
“This makes the material suitable for a vast range of applications from textile to tissue engineering.”
“Whether you are using fibres like this to make brassieres whose cup size and shape can be customized every day, or you are trying to make actuating textiles for medical therapeutics, the possibilities of Luca’s work are broad and exciting,” said Parker. “We are continuing to reimagine textiles by using biological molecules as engineering substrates like they have never been used before.”
Possible examples of use in clothing are t-shirts with cooling vents that opened when exposed to moisture and closed when dry, or one-size-fits-all clothing that stretches or shrinks to a person’s measurements.
The research is published in Nature Materials.