Flexible electronics are now one step closer to being a reality thanks to new research from the University of Michigan — the researchers there created an extremely stretchable electrical conductor out of networks of gold nano-particles embedded in elastic polyurethane.
"Polyurethane studded with gold nanoparticles can conduct electricity even when stretched to more than twice its original length. Stretchable electrodes pave the way for flexible electronics and gentler medical devices."
Image Credit: Joseph Xu
"Essentially the new nanoparticle materials behave as elastic metals," said Nicholas Kotov, the Joseph B. and Florence V. Cejka Professor of Engineering. "It's just the start of a new family of materials that can be made from a large variety of nanoparticles for a wide range of applications."
Flexible/stretchable electronics are currently a "hot" area of research, with the possibility of flexible medical implants, flexible visual displays, and flexible batteries being the primary motivation for such research.
But — needless to say — there are still some barriers to be overcome before such devices could enter wide-scale use. One of these barriers, though, may have now finally been overcome, as a result of the new research — the creation of a good conductor which is still very flexible. Previous ideas (such as wires in zigzag or spring-like patterns, liquid metals, nanowire networks) have performed considerable worse than this new design, which outperforms the best of these with regard both to stretchability and to the concentration of electrons.
"We found that nanoparticles aligned into chain form when stretching. That can make excellent conducting pathways," stated Yoonseob Kim, first author of the study, and a graduate student in the Kotov lab in chemical engineering. "As we stretch, they rearrange themselves to maintain the conductivity, and this is the reason why we got the amazing combination of stretchability and electrical conductivity." …