Scientists from McGill University, University of Illinois, and University of Science and Technology of China have conducted a comprehensive review of the latest discoveries in the field of the mechanics of 2D materials. Their findings were published in the International Journal of Extreme Manufacturing. The review focused on key mechanical properties, including elastic properties, in-plane failure, fatigue, interfacial shear/friction, and adhesion. The researchers emphasized four main aspects: recent discoveries in mechanical properties, novel deformation mechanisms, characterization technologies, and computational advancements.
Prof. Changhong Cao, the principal investigator of the leading team, expressed their hope that by reviewing the factors governing 2D material mechanics, the scientific community could develop design strategies for structural and interfacial engineering of 2D material systems for innovative applications.
While there have been significant experimental efforts in investigating the mechanical properties of 2D materials, particularly graphene, the research on the mechanics of 2D materials beyond graphene is still in its early stages. Emerging 2D materials such as metal-organic frameworks (MOFs) and covalent organic frameworks (COFs) have received limited attention in terms of mechanical investigations.
Prof. Guorui Wang, the first author of the study, highlighted the need for further research on transition-metal dichalcogenides (TMDs) beyond the well-studied ones like MoS2, WS2, MoSe2, and WSe2. Other TMDs and TMD alloys, which possess unique chemical, electronic, and magnetic properties, have not been extensively explored in terms of their mechanical properties.
The study also pointed out the lack of information regarding the mechanical behaviors of 2D heterostructures, which can be designed and assembled vertically or laterally through manual or self-assembly techniques.
Hongyu Hou, a doctoral candidate at McGill and co-first author, noted that most mechanical studies of 2D materials have focused on static or quasi-static performance, with limited exploration of dynamic behaviors under cyclic or impact loading conditions.
Furthermore, the challenges associated with handling and experimentally testing ultrathin systems highlight the importance of accurate computational methodologies to analyze the vast mechanical property space of 2D materials.
Prof. Matthew Daly, an expert in computational mechanics and co-leading author of the article, highlighted the advancements and future opportunities in computational mechanics studies of 2D materials. He discussed the limitations of Density Functional Theory (DFT) simulations in studying complex 2D systems due to high computational costs and simulation size constraints. Molecular Dynamics (MD)-based simulations offer increased accessibility but face challenges in terms of available interatomic potentials for 2D materials. Machine learning presents a new opportunity for creating interatomic potentials without requiring deep domain expertise in each specific system of interest. Additionally, strain engineering of functional properties is an important area of study for 2D materials, but significant challenges remain.
In summary, the review article provides an overview of recent discoveries and future research directions in the field of 2D material mechanics, highlighting the need for further investigation into emerging 2D materials, heterostructures, dynamic behaviors, and computational methodologies.
Source: International Journal of Extreme Manufacturing