Evgeny Birger, Nanonews NetworkA cotton shirt that can alert the wearer of allergens or instantly report that a soldier's wound is bleeding is under development by scientists from the University of Michigan.
The developers created an electrically conductive fabric by soaking cotton fiber in a vat of water containing an electrically conductive polymer and carbon nanotubes (CNTs). CNTs were absorbed into the cotton fiber and remained there after drying.
The first results of the work were published in the online journal of the American Chemical Association Nano Letters (Bong Sup Shim, Wei Chen, Chris Doty, Chuanlai Xu and Nicolas A. Kotov. Smart Electronic Yarns and Wearable Fabrics for Human Biomonitoring made by Carbon Nanotube Coating with Polyelectrolytes, – Nano Lett., Article ASAP, DOI: 10.1021/nl801495p)
The process of making a mixed material is quite simple. In addition, after such processing, the thread is able to conduct electricity, just like a metal wire, so scientists were able to connect and power the LED.
CNTs are hollow cylinders, the material of which is carbon atoms organized into flat repeating hexagonal structures; at the same time, CNTs have low weight, but high strength and electrical conductivity. The amount of CNTs deposited in the material depends on their concentration in the vat and the number of dives. The more nanotubes there are in a material, the more electrically conductive this material is.
The scope of application of cotton material with electrically conductive inclusions seems to be quite extensive: shirts of exotic models with small lights, for detecting allergens in the air, or blood on the material itself, as well as for sewing special gloves for manipulating touch screens.
To confirm the electrical conductivity of the material, scientists simply used a thread to connect to an LED and observed its radiation. When making a product from such a material, for example, a shirt, there is no need to soak it entirely in a liquid containing CNT, only a few stitched threads are enough. This efficiency of CNTs, combined with the rapidly decreasing cost of their production, should keep the cost of products with "smart" properties at a fairly low level. Of course, a shirt sewn from a material that consists entirely of threads impregnated with CNT will be quite expensive.
Thanks to cooperation with specialists in fiber materials at Cornell University, the new material feels no different from the dense cotton fabric that is used for sewing jeans. Researchers suggest that in the coming years, electrically conductive materials for clothing will appear on store shelves.
There is one "but" that both groups of researchers are well aware of. This "but" is that the safety and biological compatibility of CNTs with the human body must be unconditionally established. Scientists hope that further studies will confirm the existing data on their complete goodness.
Portal "Eternal youth" www.vechnayamolodost.ru11.12.2008