University of Virginia mechanical engineers and materials scientists, in collaboration with materials scientists at Penn State, the University of Maryland and the National Institute of Standards and Technology, have invented a “switching effect†for thermal conductivity and mechanical properties that can be incorporated into the fabrication of materials including textiles and garments. Using heat transport principles combined with a biopolymer inspired by squid ring teeth, the team studied a material that can dynamically regulate its thermal properties – switching back and forth between insulating and cooling - based on the amount of water that is present. The invention holds great promise for all sorts of new devices and materials with the ability to regulate temperature and heat flow on demand, including the “smart†fabrics. “The switching effect of thermal conductivity would be ideal for many applications, including athletics,†said John Tomko, a Ph.D. candidate in UVA'sDepartment of Materials Science & Engineeringand lead author of an article about the invention published this week inNature Nanotechnology. “This material has the potential to revolutionize active wear, unleashing the possibility of clothing that can dynamically respond to body heat and regulate temperature. For example, the biopolymer has a low thermal conductivity while dry, essentially storing body heat and keeping the athlete (and his or her muscles!) warm while not active. As soon as the wearer begins to sweat, the material could become hydrated and instantly increase its thermal conductivity, allowing this body heat to escape through the material and cool the athlete down. When the person is done training and the sweat has evaporated, the material could go back to an insulative state and keep the wearer warm again. “And while it may sound highly specialized and only for professional athletes, it would be equally useful from an apparel company perspective,†said Tomko, whose research is being conducted as part of theExSite Groupled by ProfessorPatrick Hopkinsof UVA's departments ofMechanical & Aerospace Engineering, Materials Science & Engineering andPhysics.