A new material has been created that is challenging Titanium. The material known as “metallic wood” is as strong as Titanium but five times lighter.
In a paper published in the journal Nature Scientific Reports, a team from the University of Pennsylvania and the University of Illinois in the US, Middle East Technical University in Turkey, and the University of Cambridge in the UK have made alterations to a sheet of nickel and produced an extremely strong and lightweight material they call “metallic wood”.
They refer to this material as a “metallic wood,” due to its high mechanical strength and chemical ability of metal, in addition to it having a density close to wood.
The study was led by James Pikul, assistant professor in the Department of Mechanical Engineering and Applied Mechanics at Penn Engineering.
“The reason we call it metallic wood is not just its density, which is about that of wood, but its cellular nature,” Pikul says. “Cellular materials are porous; if you look at wood grain, that’s what you’re seeing—parts that are thick and dense and made to hold the structure, and parts that are porous and made to support biological functions, like transport to and from cells.”
The researchers’ samples of the material are in sheets of just a few centimetres squared at the minute but Pikul says that sheets of several metres squared will be possible in the future, but it “will take us some time to develop the technology to get there”.
“We’ve known that going smaller gets you stronger for some time, but people haven’t been able to make these structures with strong materials that are big enough that you’d be able to do something useful,” Pikul said. “Most examples made from strong materials have been about the size of a small flea, but with our approach we can make metallic wood samples that are 400 times larger.”
Around 70 percent of the material is empty space, making its density tremendously low compared to its strength. With a density on par with water’s, a brick of the material would float.
The porous nature of the material is a feature that could be used by architects and designers, with them being able to fill the empty space with other substances.
“I imagine having a material like steel that is porous could open new possibilities for architecture in the ability for fluids to flow through it,” stated Pikul. “Wind can flow through it instead of around it. Rainwater can run through it as well. Additionally, there could be materials that are impregnated into the pores so that it adds some additional functionality, like a thermal response, or some aesthetic value, such as paint that is part of the material, so it doesn’t disappear when scratched.”
Another exciting option for this type of technology would be to have the “metallic wood” serve double duty. Due to the porosity of wood grain serving the biological function of transporting energy, the empty space in the researchers’ “metallic wood” could be infused with other materials. Infusing the scaffolding with anode and cathode materials would enable this metallic wood to serve two functions at once such as a plane wing or prosthetic leg that’s also a battery.
The next step for the researchers is to try and produce it on a larger commercial scale. Once they achieve this and larger samples are produced, they can then be put to testing, to see if it would dent like metal or shatter like glass.