Researchers in the U.S. and China say they've chemically engineered a novel, electrically conductive one-atom-thick nanomaterial flexible enough to be folded but able to support many times its own weight.
Scientists at Drexel University in Philadelphia and Dalian University of Technology in China say they material could lead to next-generation technology such as wearable energy storage devices.
Their conductive nanocomposite material, which they've dubbed MXene, is the result of a long effort by materials scientists to develop a nano-thin material for storing and distributing an electrical charge that is at the same time capable of being molded into different shapes, they said.
"Take the electrode of the small lithium-ion battery that powers your watch, for example; ideally the conductive material in that electrode would be very small -- so you don't have a bulky watch strapped to your wrist -- and hold enough energy to run your watch for a long period of time," says Drexel engineering Professor Michel Barsoum.
"But what if we wanted to make the watch's wristband into the battery? Then we'd still want to use a conductive material that is very thin and can store energy, but it would also need to be flexible enough to bend around your wrist."
The U.S. and Chinese research groups collaborated on developing the material.
Zheng Ling, a Dalian University doctoral student, spent a year at Drexel leading research that led to the MXene-polymer composites, in a program funded by the U.S. Department of Energy and the National Science Foundation.
One avenue of research involved creating MXenes with various capabilities through a process known as intercalation, in which chemical compounds in liquid form are added, settling in between layers of MXenes to alter the material's chemical and physical properties.
"This leads to a nanocomposite with a unique combination of properties," says Drexel researcher Yury Gogotsi.
The flexible MXene material can be rolled into tubes, greatly increasing its mechanical strength, suggesting research avenues that could lead to applications varying from flexible armor to uses in aerospace components, the researchers said.
Some forms have proven to be hydrophilic, suggesting the could be used in water treatments systems as membranes to facilitate desalinization or purification, since the material stays stable in water, not breaking up or dissolving.
The researchers have published the results of their testing of various MXene varieties in the Proceedings of the National Academy of Sciences.
