◎ Title : Mechanical and physical properties of atomic sheets
◎ Speaker : 이창구 교수(Sungkyunkwan University, Mechanical Engineering)
◎ Date & Time : 10.15 (Fri) 11:00
◎ Place : 응용공학동 신소재공학과 제 2세미나실
Mechanical and physical properties of atomic sheets
Recently discovered atomically thin sheets, such as graphene, has shown outstanding properties that differ from their bulk counterparts and is expected to lead to numerous applications in electronics, energy, chemistry, and mechanics. So far, the majority of the research effort has been focused on graphene and its electronic and optical properties and applications.
In contrast, their mechanical properties have barely been explored although they are equally interesting and are envisioned to have great impacts on materials design. Also other atomically thin layered materials such as MoS2 and BN have not studied as thoroughly.
In this talk, I am going to present mechanical, tribological, fluidic, optical and electrical properties of atomically thin sheets of graphene, MoS2, BN, and NbSe2. Using AFM techniques, graphene and MoS2’s mechanical properties have been measured, and graphene has shown extraordinary stiffness and fracture strength. Single-asperity contact friction measurement revealed increased friction on atomically thin sheets than their bulk materials due to “puckering effect”. I have also discovered that liquid flow over graphene generates electric potential due to charge drag effect. MoS2, when the thickness decreases down to single layer, changes from indirect to direct bangap material due to quantum confinement.