A team of researchers at North Carolina (NC) State University is developing new fabric materials that can cool itself and the wearer. A film made of small carbon nanotubes (CNT) – a key material in developing clothing that can heat or cool the wearer on demand.
A team of researchers are studying ways to make ‘smart textiles’ under professor Tushar Ghosh.
Ghosh’s group’s project is to make a new flexible material with thermoelectric properties that when worn will self-cool the wearer. Thermoelectric materials transform temperature differences into electricity and vice versa.
“Many researchers are trying to develop a material that is non-toxic and inexpensive, but at the same time is efficient at heating and cooling,” said Tushar Ghosh, co-corresponding author of the study.
The researchers were also able to optimize the thermal and electrical properties of the material, allowing the material to retain its desirable properties even when exposed to air for many weeks.
A Ph.D. student in fiber and polymer science, Kony Chatterjee explains about this project, “Current thermoelectric materials have a tendency to be heavy and brittle. Which is not so much suitable for a shirt or blouse. Many thermoelectric materials also contain toxic elements like lead.”
The innovative material was made out of carbon nanotubes, sheets of carbon atoms rolled up into cylinders’ hundreds of times thinner than a human hair. Nanotubes are robust, supple, and non-hazardous, she adds.
Nanotubes are a really promising aspect in the field of smart fabric because they do not need major processing to make them usable.
The material can cool the exterior by 1.8 degrees Fahrenheit after powered by a coin battery of only 5 volts. Kony added, “That may not sound a lot, but even this minor alteration can be noticeable on a person’s skin and encourage them to shift their thermostat.”
“If someone in Miami wears this fabric, and set the thermostat at 70 degrees Fahrenheit and move it to 73, the wearer can get anywhere between 15% to 30% in energy savings,” Chatterjee said.
This cooling fabric can help workers in personal protective equipment to stay comfortable longer by reducing the temperature just a few degrees. For example, Firefighters could safely stay in high-temperature environments for a longer period with the active cooling the thermoelectric fabric provides.
Professor Ghosh also thinks thermal comfort systems could revolutionize in health care use amid the current COVID-19 pandemic. Doctors and nurses have to wear bulky protective equipment (PPE) to prevent contamination. A self-cooling fabric can make the equipment less stifling. As the fabric can pull heat directly from or send it directly to the wearer’s skin, it could also aid control temperature for a patient suffering from heat exhaustion or hypothermia.
“Carbon nanotubes, if used appropriately, are safe, and we are using a form that happens to be inexpensive, relatively speaking. So it’s potentially a more affordable thermoelectric material that could be used next to the skin,” added Ghosh, who is the William A. Klopman Distinguished Professor of Textiles in NC State’s Wilson College of Textiles.