Weak Shock Waves on a Chip: Generation and Applications

Abstract

In conventional laser-shock experiments in solid media, shock waves are typically excited from the ablation of a photoacoustic transducer layer deposited onto the sample of interest. Unavoidably, the target materials are damaged. This leads to the necessity of changing targets after each exposure, likely lowering the shot-to-shot reproducibility and data quality, while lowering the throughput of the experiment. Motivated by the need to generate large-amplitude transient strain waves at a high repetition rate, this thesis introduces a novel platform for the non-destructive generation and amplification of acoustic waves with associated strain levels in the percent range — up to the formation of shock waves. The acoustic amplification scheme is first described. Then, owing to the capabilities of the technique to repeatedly load a material with finite-amplitude strain waves, a demonstration of the use of the platform for microscale fatigue testing is made. Finally, the strain localization of surface acoustic waves is leveraged by transiently modulating a monolayer of a transition metal dichalcogenide deposited on a substrate.