Scientists at North Carolina State University have developed highly conductive and elastic conductors made from silver nanoscale wires that may be used to develop stretchable electronic devices. Stretchable circuitry has many potential uses in the medical field, such as providing an electronic “skin” to help robots pick up delicate objects.
Dr. Yong Zhu, an assistant professor of mechanical and aerospace engineering at NC State, and Feng Xu, a Ph.D. student in Zhu’s lab have developed a new technique by placing highly conductive silver nanowires on a silicon plate and pouring a liquid polymer over the silicon substrate, then exposing the polymer to high heat.
This turns the polymer from a liquid into an elastic solid. Because the polymer flows around the silver nanowires when it is in liquid form, the nanowires are trapped in the polymer when it becomes solid. The polymer can then be peeled off the silicon plate. The silver nanowires can be printed to fabricate patterned stretchable conductors.
When the nanowire-embedded polymer is stretched and relaxed, the surface of the polymer containing nanowires buckles, and can be stretched up to 50 percent of its tensile strain, without affecting the conductivity of the silver nanowires.