Amorphous silicon carbide: a breakthrough for microchips

This new material shows remarkable strength and mechanical properties, setting a new benchmark in the of flexibly robust material. 

The amorphous structure 

Amorphous silicon carbide’s yield strength surpasses that of renowned materials such as Kevlar, making it ideal for a range of applications such as ultra-sensitive microchip sensors, advanced solar cells, innovative space exploration technologies, and DNA sequencing. 

a-SiC has a tensile strength of 10 GigaPascal (GPa), which, according to Professor Norte, means that to achieve a similar tensile stress, one would need the equivalent weight of ten medium-sized cars attached to the end of a strip of a-SiC before it would break. 

Speaking to Electronic Specifier on where he sees the most immediate and impactful applications of a-SiC, Professor Norte commented: “The most immediate impact would be in sensor applications where high strength materials allow for higher tensile forces in vibrating elements that people can now make on a microchip. These higher tensile forces allow the vibrating elements to be increasingly more sensitive sensors.”

Unlike traditional crystalline materials such as diamonds, a-SiC has an amorphous structure, meaning its atoms are arranged in a random, disordered pattern. But, rather counterintuitively, this lack of uniform atomic arrangement contributes significantly to the material's overall strength and versatility – which challenges the conventional notions of material science. 

Material testing, scalability, and production

The team at TU Delft tested the strength of a-SiC by using nanostrings to induce high tensile forces. The nanostrings approach, where the use of extremely thin nano-scale strings or wires are integrated into microchip architecture, represents a marked leap in material testing methodologies, ensuring precision, and setting the scene for future advancements in the field. 

“In terms of emerging fields, there are several emerging fields that require nanoscale elements that can withstand large forces that create tensile forces in suspended materials. For instance, there are now interstellar space missions like Starshot Breakthrough which require ultra-strong very thin reflectors as sails that are accelerated to 1/5 of the speed of light with high-powered lasers. This is something our lab is currently working on,” said Norte.

Unlike materials like graphene or diamonds, which are challenging to produce in large quantities, a-SiC can be manufactured at wafer scales. This scalability makes it a more practical choice for widespread application in various industries. 

A range of applications 

In the sphere of microchip sensors, the material's strength and stability could lead to the development of more sensitive and reliable sensors, which are crucial in numerous critical applications. The durability and efficiency of a-SiC could also significantly enhance solar cell technology, leading to more effective and sustainable energy solutions. 

In space exploration, a-SiC’s robustness could offer enhanced protection for spacecraft and satellites against extreme environmental conditions, thus improving the safety and longevity of space missions. In the biotechnology sector, particularly in DNA sequencing, the precision and stability of a-SiC could lead to more accurate and efficient sequencing techniques, potentially accelerating breakthroughs in scientific research. 

To integrate this material into manufacturing and design processes can be a challenge.

“Mechanically, this material performs extremely well so for nanomechanical technologies it is very interesting. Optically, our initial experiments show that its optical properties are not great. By this I mean that its optical absorption is high. This can lead to heating and optical losses which are usually not preferred. We would like to improve this optical absorption by changing the chemistry so that we can use this material for optical microcircuits. This would really open up its uses in nanophotonics and even interstellar missions.”

Future impact 

The discovery of a-SiC represents a paradigm shift in how we approach the development and application of new materials. With its strength, ease of production, and potential for diverse applications, a-SiC is set to transform numerous industries. 

The recent publication of a detailed study on a-SiC in Wiley highlights its significance. The study reveals that a-SiC strings with high aspect ratios have demonstrated exceptional mechanical modes at room temperature, indicating their suitability for high-performance applications in dynamic environments.

A new phase of material science may be dawning with the advent of a-SiC – indicating a future rich with technological possibilities.