17 September 2024 - UCLouvain: Seminar of E. TOCHIGI
Operation of a MEMS-based in situ TEM mechanical testing system and applied research
Eita Tochigi
Institute of Industrial Science, The University of Tokyo, Japan
Mechanical properties of crystalline materials are governed by the nucleation and propagation of lattice defects. Investigating their behavior under loading conditions is the key to understanding the deformation or fracture phenomena of crystals. In situ transmission electron microscopy (TEM) mechanical testing is a powerful technique to directly observe the dynamic behavior of lattice defects and has widely been employed for materials research. However, in situ TEM mechanical testing has typically been limited to application in conventional TEMs because of physical size limitations of sample holders with mechanical machinery. To enable in situ mechanical testing in modern high-performance TEM/scanning TEM (STEM), we have developed a new experimental system. The core mechanism of our experimental system is a MEMS device. The MEMS device has two cantilevers driven by electrostatic actuators. The cantilevers can be controlled by external voltage supply with an accuracy of less than sub nanometers and sub micro-Newton, which allows to perform in situ loading testing under atomic-resolution imaging. In the presentation, we will explain the mechanism and operation procedures of our experimental system with atomic-resolution STEM and discuss some applied research, including observations of dislocation reactions, dislocation emission and crack propagation.
The seminar will be given at 3:30pm in UCLouvain at IMAP (Materials and process engineering)
Room Shannon (building Maxwell, room a105, 1st floor)
Place Sainte Barbe 2, 1348, Louvain-la-Neuve