Researchers developed the gold nanomesh electrodes with ‘ultra-high stretch ability’ that provided good electrical conductivity as well as transparency and flexibility.

The material also has potential applications for biomedical devices, said Zhifeng Ren, a physicist at the University of Houston and lead author of the research.
The researchers reported that gold nanomesh electrodes, produced by the novel grain boundary lithography, increase resistance only slightly even at a strain of 160 percent or after 1,000 cycles at a strain of 50 percent.

The nanomesh, a network of fully interconnected gold nanowires, has good electrical conductivity and transparency, and has ‘ultrahigh stretch ability’, researchers said.
Unlike silver or copper, gold nanomesh does not easily oxidize, which Ren said causes a sharp drop in electrical conductivity in silver and copper nanowires.

Research associates Chuan Fei Guo said that the group is the first to create a material that is transparent, stretchable and conductive as well as the first to use grain boundary lithography in the quest to do so.
More importantly it is the first to offer a clear mechanism to produce ultrahigh stretch ability, he said.

The grain boundary lithography involved a bilayer lift-off metallization process, which included an indium oxide mask layer and a silicon oxide sacrificial layer and offers good control over the dimensions of the mesh structure.

"This is very useful to the field of foldable electronics. It is much more transportable," Guo said.

Ren noted that, although gold nanomesh is superior to other materials tested, it even broke and electrical resistance increased when it was stretched. But he said the conductivity resumed when it was returned to the original dimensions.