Materials

Room temperature metalworking inspired by insects and crab shells

A model of a honeybee head, made using the new metalworking method inspired by the natural way insects build their shells
SUTD
A model of a honeybee head, made using the new metalworking method inspired by the natural way insects build their shells
SUTD

Metalworking usually requires very high heat and pressure, but scientists in Singapore have now demonstrated a way to make very pure metal structures at room temperature. It’s inspired by the exoskeletons of crabs and insects.

From the days of blacksmiths using furnaces and anvils, to the huge energy-guzzling industrial facilities of today, bending metals to our will takes a lot of heat, energy and effort. But as with many things, nature might have found a way long ago.

Metallic compounds are sometimes found in the tough exoskeletons of arthropods, like crabs, lobsters, insects and spiders. These shells are mostly formed out of a tough protein called chitin, which hardens through tanning and dehydration. Chitin and other related molecules like chitosan can then pull in metal particles from the environment, to reinforce the animals’ shells.

Now, scientists at the Singapore University of Technology and Design (SUTD) have used this ability to make metal structures at room temperature and pressure. The researchers made colloidal mixtures of metals, then poured them into small amounts of chitosan dissolved in water.

As the water evaporates out of the mixture, the chitosan molecules begin to pull the metal particles together, in a similar way to how it works in these armored animals.

The end result is a continuous solid piece of metal in a desired shape, with 99.5% purity. These structures not only have properties of metals, including good electrical conductivity, but more intriguingly they’re still compatible with other biomaterials, even with only a small amount of added chitosan. That means they could be incorporated into materials like wood and cellulose.

While the metals made through this method aren’t particularly strong, the team says it could still be a useful way to make some metallic components for electronics. The next step is to develop the process further to make biodegradable electronic components.

The research was published in the journal Advanced Functional Materials. The team demonstrates the technique in the video below.

Source: SUTD via Asia Research News

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3 comments
Trylon
The researchers aren't completely right. We don't always need heat to form metals. Back in school, we learned how to hammer sheet metal into shape by hand. And for heavier, bigger parts, there's also cold forging.
windykites
What about electroplating? That works well, and can be made to any thickness.
fen
The two people above seem to misunderstand. This isn't about just forming metal, but making the metal too. So the first Person Trylon who said you can form a sheet of metal by hammering with no heat, sure you can, but you needed heat to make the sheet of metal, same for cold forging the initial sheet of metal came from a forge. This process you would make the metal on site.

Electroplating is probably more simillar, but a plate of metal over a substance in any thickness you want is slightly different. I think the biggest difference would be, with this metal you could print a circuit board in a sphere, and the substance itself would be the board, no plating needed, its a metal board, why anyone would want that, I dunno, but it could revolutionize watches and whatnot if we could contour the circuit boards in a cheap way. You could pump out thousands of curved circuit boards maybe.

I dunno, but the process is really interesting and probably open up a bunch of cool stuff.