The material is made of molecular fragments which are jumbled and disordered, but can still conduct electricity extremely well.
According to the popular science magazine Nature, the material disobeys all the rules.
Jiaze Xie, the first author on the paper said: “In principle, this opens up the design of a whole new class of materials that conduct electricity, are easy to shape, and are very robust in everyday conditions,” said John Anderson, an associate professor of chemistry at the University of Chicago and the senior author on the study. “Essentially, it suggests new possibilities for an extremely important technological group of materials."
About 50 years ago, scientists were able to create conductors made out of organic materials, using a chemical treatment known as “doping,” which sprinkles in different atoms or “impurities” throughout the material. The fact that these materials are more flexible and easier to work with than conventional metals makes them attractive, but the problem is that they aren’t particularly stable and may lose their conductivity if exposed to moisture or if the temperature rises too high.
Boffins thought material needed straight, orderly rows in order to conduct electricity efficiently.
Then Xie began experimenting with some materials that were discovered years ago, but largely ignored since. He strung nickel atoms like pearls into a string of molecular beads made of carbon and sulfur, and began testing.
The material easily and strongly conducted electricity and was stable.
“We heated it, chilled it, exposed it to air and humidity, and even dripped acid and base on it, and nothing happened,” said Xie. That is enormously helpful for a device that has to function in the real world.
Xie, Anderson, and their lab worked with other scientists around the university to try to understand how the material can conduct electricity. They think that the material forms layers, like sheets in a lasagna. Even if the sheets rotate sideways, no longer forming a neat lasagna stack, electrons can still move horizontally or vertically—as long as the pieces touch.
The end result is unprecedented for a conductive material. “It’s almost like conductive Play-Doh—you can smush it into place and it conducts electricity,” Anderson said.
The scientists are excited because the discovery suggests a fundamentally new design principle for electronics technology. Conductors are so important that virtually any new development opens up new lines for technology, they explained.
One of the material’s attractive characteristics is new options for processing. For example, metals usually have to be melted in order to be made into the right shape for a chip or device, which limits what you can make with them, since other components of the device have to be able to withstand the heat needed to process these materials.
The new material can be made at room temperature. It can also be used where the need for a device or pieces of the device to withstand heat, acid or alkalinity, or humidity has previously limited engineers’ options to develop new technology.
The team is also exploring the different forms and functions the material might make. “We think we can make it 2D or 3D, make it porous, or even introduce other functions by adding different linkers or nodes,” said Xie.
