Researchers at ETH Zurich develop super light ‘plastic’ gold, which could make new electronic devices much lighter

A team of researchers at the renowned ETH Zurich in Switzerland have developed an extremely lightweight 18-carat gold alloy. The new material looks like any other 18 carat gold alloy, such as those made with copper and zinc, however, it behaves much differently thanks to its specially developed composition. The new plastic-like substance consists of gold nanocrystals suspended in a network of protein fibers and polymer latex, making the new material extremely lightweight and allowing it to behave like plastic.

Along with having the material properties of plastic, the composition of the new gold alloy is highly tunable and can be altered to produce a variety of effects. “This gold has the material properties of a plastic,” says material scientist Raffaele Mezzenga, who was part of the team that developed the material, “as a general rule, our approach lets us create almost any kind of gold we choose, in line with the desired properties.“

The new material retains the excellent conductivity of gold and is therefore an ideal match for use in future lightweight electronics applications. An obvious application for it would be the newly emerging space industry. Its overall density is just 1.7 g/cm3, much lower than the typical 15 g/cm3 of other 18-carat gold alloys. “This new 18-carat gold can fill a niche which is currently unoccupied in the realm of industrially relevant gold blends and open the way to unexplored applications,” the researchers wrote in their paper detailing the material. Another significant advantage of the material is that it becomes malleable at just 105 degrees Celsius, as opposed to 1,064 degrees required to melt pure 24-carat gold, therefore making it very easy to work with using minimal tooling.