时间：2019年1月8日14:00

地点：综合1号实验楼602

报告人：Zhaohe Dai，Department of Engineering Mechanics, University of Texas at Austin

报告题目：Mechanics of Atomically Thin Films – 2D Materials

Two-dimensional (2D) materials are atomically thin crystals with unique properties that lend well to next-generation batteries, nanocomposites, and ultrathin electronic and optoelectronic devices. Though each application exploits a different key property of the 2D material, they all implicitly depend on its mechanical behaviors for structural reliability and even functional performances. In 2D material devices, particularly, the mechanical deformations of 2D material couples with new physics tightly, termed mechanoelectronics. These facts bring the necessity of understanding the mechanics of these atomically thin materials. Also, the intrinsic multiscale nature of 2D materials makes the associated mechanics characterizations and modeling quite interesting yet challenging.

To deal with these outstanding issues, we developed experiment-based studies from perspectives of mechanics of 2D materials as thin films, mechanics of 2D-material-based interfaces, and mechanics of 2D-material-enabled applications such as nanocomposites and flexible electronics. In this talk, I will focus on our recently developed micro/nanobubble tests of 2D materials that can offer a versatile platform for mechanics purposes. The 2D material bubble can form spontaneously during the transfer process and also be fabricated in a controlled manner. Though the profile of the bubble follows a simple spherical cap shape, there are plenty of subtleties underneath these bubbles, knowing these can allow for the measures of important mechanical parameters, such as Young’s modulus, adhesion, and friction as well as mechanics-coupled physics such as band gap and pseudomagnetic fields. I will conclude by discussing the multiscale mechanics appearing in these 2D material micro/nanobubbles. Part of results involving in this talk has been published in PRL (2017), PNAS (2018), PRL (2018), and Adv. Mater. (2019).

About the presenter:

Zhaohe Dai is currently pursuing his Ph.D. at the University of Texas at Austin. He received his B.S. in modern mechanics from the University of Science and Technology of China in 2013 and his M.S. in solid mechanics from the Institute of Mechanics, Chinese Academy of Sciences in 2016. His research interests are in the mechanics of 2D materials and their applications. Zhaohe has published more than 30 peer-reviewed journal articles, many of which have appeared in high impact journals such as PRL, PNAS, Advanced Materials, Advanced Functional Materials and so on. He has 2 issued Chinese patents. His research has been highlighted by news media such as APS physics, Physics world, Physorg, Nanotech and so on.