Uniformity of planar shock waves generated by vaporizing foil actuator and its application to microfabrication

This study explores the feasibility of using planar shock waves generated by vaporizing foil actuators (VFA) in microfabrication technologies. We conducted experiments to investigate the generation and propagation of these shock waves by detonating actuators at relatively low current densities. The measurements of discharge voltage and current, coupled with high-speed imaging, indicated that planar shock waves result from the convergence of multiple shock waves due to the non-uniform heating and vaporization of the actuator. These experiments also demonstrated that the pressure within the shock waves can be precisely characterized. In microscale embossing experiments, metal workpieces exhibited uniform forming, whereas polymeric workpieces demonstrated non-uniform forming. This distinction underscores the utility of polymer workpieces in elucidating the heterogeneity of explosions in VFA applications. The successful deformation of metal workpieces at the nanoscale further confirmed the potential of VFA for precise microfabrication. This research highlights the critical influence of material type on the outcomes of VFA-induced forming and offers significant insights into the dynamics of shock waves necessary for optimizing microfabrication processes.