Stanford Scientists Use Light to Weld Nanowires

Stanford engineers said they succeeded in welding tiny nanowires with a "blast of light".

The technique could turn out to be much more effective than the current method that uses heat or pressure to create a mesh nanowires, which usually damages the wires.

“When two nanowires lay crisscrossed, we know that light will generate plasmon waves at the place where the two nanowires meet, creating a hot spot. The beauty is that the hot spots exist only when the nanowires touch, not after they have fused. The welding stops itself. It’s self-limiting,” said Mark Brongersma, an associate professor of materials science engineering at Stanford and one of the authors of a related paper published in the journal Nature Materials.

Most importantly, the process, also described as "precision heating", leaves all other wires unaffected. As a result, nanoscale welding can be achieved with greater speed and control, while the researchers claim that they can use the method to also create much stronger meshes. An interesting application could be a technology to create super-thin plastics and polymers that could even be used as coatings on other surfaces. For example, the scientists sprayed a solution containing silver nanowires in suspension on the plastic and dried it. Using their light-welding technology, they created an "ultrathin" layer of welded nanowires.

There was no information about a potential commercial use of the technology, but the researchers said that they envision "interesting, simple and large-area processing schemes for electronic devices — solar, LEDs and touch-screen displays, especially."