New amorphous material produces some strong string

Researchers at Delft University of Technology in the Netherlands, led by assistant professor Richard Norte, have unveiled a remarkable new material with potential to impact the world of material science. Termed amorphous silicon carbide (a-SiC), this novel material possesses several useful mechanical properties, including exceptional strength.

The range of potential applications is vast. From ultra-sensitive microchip sensors and advanced solar cells, to pioneering space exploration and DNA sequencing technologies. The advantages of this material’s strength combined with its scalability make it exceptionally promising. The researchers describe the new amorphous material in a paper in Advanced Materials.

“To better understand the crucial characteristic of ‘amorphous’, think of most materials as being made up of atoms arranged in a regular pattern, like an intricately built Lego tower,” explains Norte. “These are termed as ‘crystalline’ materials, like for example, a diamond. It has carbon atoms perfectly aligned, contributing to its famed hardness.”

Amorphous materials, on the other hand, are akin to a randomly piled set of Legos, where atoms lack consistent arrangement. But contrary to expectations, this randomization doesn’t result in fragility. In fact, amorphous silicon carbide is a testament to the strength that can emerge from such randomness.

The tensile strength of this new material is 10 GigaPascal (GPa). “To grasp what this means, imagine trying to stretch a piece of duct tape until it breaks,” says Norte. “Now if you’d want to simulate the tensile stress equivalent to 10GPa, you’d need to hang about ten medium-sized cars end-to-end off that strip before it breaks.”

The researchers adopted an innovative method to test this material’s tensile strength. Instead of using traditional methods, which might introduce inaccuracies from the way the material is anchored, they turned to microchip technology. By growing tiny strings of amorphous silicon carbide on a silicon substrate and suspending them, they leveraged the geometry of the nanostrings to induce high tensile forces.

By fabricating many such structures with increasing tensile forces, they meticulously observed the point of breakage. This microchip-based approach not only ensured unprecedented precision but also paves the way for future material testing.

“Nanostrings are fundamental building blocks, the very foundation that can be used to construct more intricate suspended structures,” Norte says. “Demonstrating high yield strength in a nanostring translates to showcasing strength in its most elemental form.”

What also sets this material apart is its scalability. Graphene, a single layer of carbon atoms, is known for its impressive strength but is challenging to produce in large quantities. Diamonds, though immensely strong, are either rare in nature or costly to synthesize. In contrast, amorphous silicon carbide can be produced at wafer scales, leading to large sheets of this incredibly robust material.

“With amorphous silicon carbide’s emergence, we’re poised at the threshold of microchip research brimming with technological possibilities,” concludes Norte.

This story is adapted from material from Delft University of Technology, with editorial changes made by Materials Today. The views expressed in this article do not necessarily represent those of Elsevier. Link to original source.