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.
Production of electrically conductive biological objects at ambient conditions
Source: SUTD via Asia Research News
