CHARACTERIZATION OF THE PULSED NEEDLE-FREE MICRO-INJECTOR IN THE MEDICAL DELIVERY SYSTEM

This paper describes the development of the needle-free injection with a pulsed micro-injector. The novel injection system consists of a micro-injector, a solenoid valve with an electron-control system and a high pressure liquid supply system. The diameters of the orifice are 200µm~ 300µm. The performance of both pulsed and continuous injections is characterized. Results show that the mass flow rate is increased linearly for the liquid pressure ranging from 50bar to 125bar. The jet velocity increases from 50.6m/s to 104m/s as the liquid pressure increases from 50bar to 125bar. Penetration test to the soft solid materials shows that the penetration depth is increased from 2mm to 7mm depending on the injection power under single pulsed injection. It is believed that the technique will be useful for the drug delivery as well as the localized tumor treatment.