이번 학기 세 번째 콜로퀴움은 성균관대학교 기계공학과 이창구 교수님을 모시고 콜로퀴움을 개최하오니, 학과 구성원 여러분의 많은 참여를 부탁 드립니다.

아            래

1. Title: Mechanics of Atomically thin materials

2. Speaker: 이  창  구 교수님 (성균관대학교 기계공학과)

3. Date & Time: Sep 20(Wed.) 2023.  4:30 PM

4. Place: Natural Science 1,  Room No. 31214

5. Abstract: Atomically thin 2D materials have shown outstanding properties that differ from their bulk counterparts and are expected to lead to numerous applications in electronics, energy, chemistry, and mechanics. With hexagonal lattice structures, they have very high mechanical properties due to strong bond between the in-plane atoms. However, there are no dangling bonds in out-of-plane direction, and their surface energy is low. In this talk, I am going to present mechanical and tribological properties of graphene, h-BN, and MoS2. Using AFM nanoindentation and friction force measurement techniques, 2D materials’ basic mechanical properties have been characterized. Young’s modulus and strength of single- and multi-layer graphene, functionalized graphene, h-BN, and MoS2 have been experimentally measured by the AFM indentation. Single layer graphene has extraordinary stiffness and fracture strength. However, when graphene gets thicker or functionalized, it becomes weak due to defects and higher chance of fracture. h-BN is as strong as graphene, but thicker h-BN samples show better strength than graphene of the same layer number. MoS2 is relatively weak compared to graphene and h-BN, but still is strong. Also, when 2D materials are scanned by AFM tip, the surface has low friction. However, with increasing thickness the friction decreases. This is due to the bending stiffness difference with varying thickness. Large area graphene also has low friction coefficient and show the potential as a solid lubricant coating material.