Fascinating Metal News: Liquid Metal, Bacteria-Killing Surfaces and the Earth Is Leaking Iron

Fascinating Metal News: Liquid Metal, Bacteria-Killing Surfaces and the Earth Is Leaking Iron

14th April 2020

It is easy to think that metals have always existed in the same state and will always continue to be the same. Yet, a look at some of the most fascinating recent news stories tells us that there are new discoveries constantly being made.

The Laser That Kills Bacteria on Metal Surfaces

Engineers working out of the Purdue University have possibly made a breakthrough in how to keep metal surfaces free of bacteria. They discovered that applying a laser treatment to the metal can turn it into a bacteria-killer.

They carried out this research on smooth copper surfaces, where bacteria can typically live for days. It works by giving the metal a rougher texture with nano-material coatings, according to the study which was published recently in the Advanced Materials Interfaces journal.

The copper surface can then instantly destroy bacteria with antibiotic resistance, with Meticillin Resistant Staphylococcus Aureus one example of this. It isn’t yet known whether this could work on CE accredited fabrications and other types of metal surface.

Rahim Rahimi is assistant professor of material engineering at Purdue. He pointed out that the laser-treated surface will only kill bacteria under normal conditions and that it doesn’t work on viruses.

The First Metal Liquid Lattice

If you have ever seen the Terminator 2 movie then you already know that liquid metal has the prospect of being used to create terrifying killer robots. However, Pu Zhang has less destructive plans for his creation.

Zhang is an assistant professor of mechanical engineering at the Thomas J. Watson School of Engineering and Applied Science. He and his students have created something that he believes is the world’s first liquid metal lattice.

It is a mixture of bismuth, indium and tin that is known as Field’s Alloy in honour of its creator, Simon Quellen Field. What is interesting about this alloy is that it turns into liquid at its melting point of 62°C (144°F).

The team added a rubber shell to it, using a combination of 3D printing, conformal coating and vacuum casting. The shell keeps the metal in place. It is solid and strong, but most amazing is the fact that it returns to its original shape after being crushed.

Why the Earth Might be Leaking Iron

Charles Lesher is professor emeritus of geology at UC Davis. He is also the lead author of a new study that suggests that the molten core of our planet might be leaking iron.

You would have to dig down approximately 1,800 miles below the surface of the Earth to find the place where the liquid iron core and the rocky mantle meet. This is where the temperature rises dramatically, by over a thousand degrees, as you enter the core.

The key finding in this study is that heavier iron isotopes may head towards areas with cooler temperatures, while lighter isotopes go back to the hotter core.

If their findings are found to be correct, it means that iron ore from the Earth’s core has been seeping into the mantel over billions of years. They even suggest that some may reach the surface in lava eruptions in certain places.