In a groundbreaking discovery, researchers have unveiled a new two-dimensional (2D) carbon material that is tougher than graphene and can resist cracking under pressure—an issue that has long challenged materials scientists. While carbon-based materials like graphene are renowned for their strength, they are also notoriously brittle, with cracks quickly spreading once formed, leading to sudden and catastrophic fractures. The newly developed material, known as monolayer amorphous carbon (MAC), overcomes this weakness, proving to be eight times tougher than graphene, according to a recent study by Rice University scientists and collaborators, published in Matter.
Like graphene, MAC is a 2D material that is just one atom thick. However, its atomic structure is unique compared to graphene. While graphene features a highly ordered hexagonal lattice, MAC is a composite material with both crystalline and amorphous regions. This hybrid structure is the key to its enhanced toughness, preventing cracks from easily propagating and allowing the material to absorb more energy before breaking.
“This unique design prevents cracks from propagating easily, allowing the material to absorb more energy before breaking,” said Bongki Shin, a graduate student in materials science and nanoengineering at Rice University and the first author of the study.
The discovery marks a significant advancement for 2D materials, which have already sparked transformative innovations in fields like electronics, energy storage, sensors, and wearable technologies. Despite their exceptional properties, the brittleness of many 2D materials has limited their practical applications—until now.
The ability of MAC to resist cracking stems from its composite structure, which blends ordered (crystalline) and disordered (amorphous) regions. Researchers suggest that this approach—combining both crystalline and amorphous elements within 2D materials—could be a valuable strategy to reduce brittleness and increase toughness in other materials as well.
“We believe that this structure-based toughening strategy could work for other 2D materials, so this work opens up exciting possibilities for advanced materials design,” said Jun Lou, a professor of materials science, nanoengineering, and chemistry at Rice University, and a corresponding author on the study.
Researchers also explored two approaches to enhancing the toughness of 2D nanomaterials: “extrinsic toughening,” which involves reinforcing the thin films with additional nanostructures, and “intrinsic toughening,” which modifies the material’s internal structure itself. MAC represents an ideal example of intrinsic toughening, as the in-plane design incorporates both crystalline and amorphous regions, creating a more durable nanocomposite.
To study how the MAC material resists cracking, the team conducted in situ tensile testing inside a scanning electron microscope, which allowed them to observe cracks forming and propagating in real-time. This technique provided direct insight into how the composite structure of MAC resists the typical fracture patterns seen in other 2D materials.
Additionally, molecular dynamics simulations led by Markus Buehler at MIT helped researchers zoom in at the atomic level to better understand how the mix of crystalline and amorphous regions influences the material’s fracture energy. “This hadn’t been done before because creating and imaging an ultrathin, disordered material at the atomic scale is extremely challenging,” explained Yimo Han, assistant professor of materials science and nanoengineering at Rice University and a corresponding author. “However, thanks to recent advances in nanomaterial synthesis and high-resolution imaging, we were able to uncover a new approach to making 2D materials tougher without adding extra layers.”
This breakthrough has profound implications for the future of 2D materials and their applications. By introducing a more flexible, durable design, scientists can extend the usability of 2D materials in demanding environments and industrial applications, where resistance to cracking is essential. The development of MAC opens up new avenues for creating stronger, more reliable materials for everything from energy storage to flexible electronics, moving one step closer to the widespread use of 2D materials in everyday technology.
As the research continues, scientists are hopeful that the toughening strategy employed in MAC can be applied to other 2D materials, making them more practical for real-world use while maintaining their exceptional strength and conductivity.
By Impact Lab
