Nanotube-coated Yarn Fabric Detects Blood, Health of Wearer

Engineers at the University of Michigan have created a carbon nanotube-coated “smart yarn” that conducts electricity. This, according to the university report, could be woven into fabrics in order to detect blood or monitor the health of the wearer. The nanotube-coated smart yarn was shown to conduct enough electricity from a battery to power a light-emitting diode device. Researchers could use its conductivity to design garments that detect blood.

“Currently, smart textiles are made primarily of metallic or optical fibers," explained Nicholas Kotov, a professor in the departments of chemical engineering, materials science, and engineering and biomedical engineering, in the university report. "They’re fragile. They’re not comfortable. Metal fibers also corrode. There are problems with washing such electronic textiles. We have found a much simpler way—an elegant way—by combining two fibers, one natural and one created by nanotechnology."

Kotov and Bongsup Shim, a doctoral student in the department of chemical engineering, are among the co-authors of a paper on this material currently published online in Nano Letters. The researchers say it can be woven into smart textiles that would be softer and more practical than current designs for electrically conducting fabrics. As reported, to make these e-textiles, the researchers dipped 1.5-mm thick cotton yarn into a solution of carbon nanotubes in water, and then into a solution of a special polymer in ethanol. After being dipped a few times into both solutions and dried, the yarn was able to conduct enough power from a battery to illuminate a light-emitting diode device. Kotov added, "After just a few repetitions of the process, this normal cotton becomes a conductive material because carbon nanotubes are conductive.”

The only perceptible change to the yarn is that it reportedly turned black from the carbon but it remained pliable and soft. In order to use its conductivity, the researchers added the antibody anti-albumin to the carbon nanotube solution, which reacts with albumin, a protein found in blood. When the researchers exposed their anti-albumin-infused smart yarn to albumin, they found that the conductivity significantly increased.

This new material is reportedly more sensitive and selective, as well as more simple and durable, than other electronic textiles. Suggested applications potentially include clothing to detect blood in high-risk professions where the clothing could send a distress signal to a central command post, if the wearer were unconscious and injured.

“The concept of electrically sensitive clothing made of carbon nanotube-coated cotton is flexible in implementations and can be adapted for a variety of health monitoring tasks, as well as high performance garments,” Kotov said. According to the report, it is conceivable that clothes made from this material could be designed to harvest energy or store it or provide power for small electronic devices, although such developments are many years away and pose many challenges.

The personal care industry has noted the development of intelligent textiles previously, and has considered them for smart delivery in applications such as fragrance release and skin conditioning treatments. While it may seem a long way off, engineers are beginning to make it more feasible. Perhaps nanotechnology is providing the means to this end.

The paper published online in Nano Letters is titled, “Smart Electronic Yarns and Wearable Fabrics for Human Biomonitoring Made by Carbon Nanotube Coating with Polyelectrolytes.” Other contributors are with Jiangnan University in China. This research was funded by the National Science Foundation, the Office of Naval Research, the Air Force Office of Scientific Research and the National Natural Science Foundation of China.

For more information, visit the University of Michigan Web site.

More in Tech Transfer