High-velocity projectile launcher of LIPIT: Utilizing stress wave driven by laser-induced glass breakdown

Abstract

Laser-induced projectile impact testing (LIPIT) provides a desktop-level platform for analyzing the high-strain-rate impact response of materials. However, the projectile velocity without debris is limited by the damage to the elastomer membrane under intense plasma pressure. This work investigates a novel method for launching projectiles by utilizing the stress wave generated through laser-induced breakdown within the glass substrate, avoiding the direct impact of high-pressure plasma on the elastomer. The experimental results indicate that the launch velocity is increased through the new stress-wave-driven method. This improvement is attributed to the decreased susceptibility of the expanded membrane to rupture under limited thermal effects and its uniform expansion morphology. Based on the new stress-wave-driven principle, we propose a simplified launcher configuration of “glass-polyimide” for higher launch velocity. Furthermore, a correlation between projectile velocity and variables such as laser pulse energy, defocus distance, and projectile parameters is proposed through analytical analysis and validated by experimental data. The results indicate that the launcher with the proposed configuration can increase the maximum launch velocity of projectiles with diameters ranging from ten microns to sub-millimeters, addressing the need for independent ballistic testing at the sub-millimeter scale.