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A MEMS-Based Platform for Strain Engineering of Two-Dimensional Materials
Two-dimensional (2D) materials have attracted tremendous attention in multiple research disciplines since graphene was first isolated from graphite in 2004, owing to its atomic thickness and unique electrical, optical, and mechanical properties, which are different from their bulky counterparts. As for traditional materials where the properties can be tuned by strain, strain engineering of 2D materials is of vital importance, and it is a subarea in 2D materials which is under fast development. This dissertation introduces a novel MEMS-based platform for strain engineering of 2D materials, which has the ability to induce pure in-plane strain and test property changes of 2D materials in-situ, achieving functions not available for currently existing straining platforms. Graphene was employed as a representative of 2D materials to demonstrate the application of this platform in three research areas. First, a widely tunable MEMS-based doubly clamped graphene resonator is demonstrated. The relation between in-plane strain and Q-factor of a graphene resonator with free edges for a large tuning range was experimentally established for the first time. New strain-related energy dissipation mechanisms, namely folding edge and dislocation-induced energy dissipation, were proposed to explain the observed behaviors. Second, I show the results of a collaborated work studying how strain affects the resistance of multi-layer graphene in low temperature under a magnetic field using the MEMS-based straining platform. Third, I briefly demonstrate the in-situ TEM mechanical testing capability of this novel platform dedicated to 2D materials. The MEMS-2D material hybrid device will not only serve for research purposes in understanding the fundamental physics of strain-induced property changes in 2D materials, but also has potential applications in future generation communication systems, sensing and memory electronics.
Materials science|Nanoscience|Energy|Low Temperature Physics|Information Technology|Technical Communication|Mechanics|Mechanical engineering|Remote sensing
Huang, Yifan, "A MEMS-Based Platform for Strain Engineering of Two-Dimensional Materials" (2020). ETD collection for University of Nebraska - Lincoln. AAI28258877.