Spinning Powder Into Yarn

Using a scant portion of carbon nanotube sheets as support material, researchers at the University of Texas, Dallas, have devised a method to spin powders into yarn that maintains the properties of the original powder (Science, DOI: 10.1126/science.1195912). The technique, known as biscrolling, begins with a fine, weblike sheet of carbon nanotubes. Particulate or nanofiber powders are applied to the sheet via liquid-based methods, sputtering, or with an electrostatic powder-coating gun. Then stacks of the coated sheets are twisted into scrolls of yarn, with the particulate matter filling the scroll “galleries,” or spaces between the support material. The researchers, led by Ray H. Baughman, have used the technique to create yarns made of superconductors, lithium-ion battery materials, graphene ribbons, catalytic nanofibers for fuel cells, and titanium dioxide for photocatalysis. They also show that the yarns can be woven into fabric, tied into knots, and washed in a washing machine without losing their powdery particles. The researchers envision the technology could be used to make smart clothing, self-cleaning textiles, and solar cells.