Design and Optimization of a Miniature Shock Tube -Driven Needle Free Injector

This research presents a novel, shock tube-powered, needle-free drug delivery system that solves the problems of traditional injection methods. This portable device is 100 mm long, weighs 300 g, and uses controlled shock waves to create high-speed microjets (Mach 1.2–1.5) through an optimized convergent-divergent nozzle (0.25 mm throat, 0.35 mm exit). The aluminum casing provides portability, while the tungsten carbide nozzle offers greater durability and accuracy. Theoretical and experimental studies validate that the device penetrates uniformly to depths between 200 and 470 µm, so it should work well with a variety of skin types. The device works at safe parameters (1.2 bar initial pressure,