Design and analysis of a detonation-driven mechanism for needle-free liquid jet injection

Needle-free liquid jet injection for drug delivery is a biomedical concept aimed to reduce many drawbacks associated with the use of hypodermic needles such as bio-hazard waste, cross contamination and needle phobia. One of the key elements which limits the current technologies is the ability to provide sufficient power to generate a high-speed liquid jet with a velocity on the order of 100 to 200 m/s, created by using a piston to compress a column of fluid through a micro-orifice. This jet pierces the skin and effectively delivers larger quantities of highly viscous medication to a target area at different skin layers. This study experimentally explores the idea of harnessing the energy release from a gaseous detonation for the high power requirement necessary to drive the injection piston and pressurize the medication. The feasibility and performance of the detonation-driven mechanism are assessed against available technologies such as air-powered and servo-controlled, high precision injection systems. The comparison aims to illustrate basic relationships between different injection characteristics and detonation parameters used in this proposed controlled release process.