Transdermal drug delivery using needle free jet injections entails ejection of a liquid drug through a fine nozzle at elevated pressure, thus generating a narrow high-velocity fluid jet readily penetrable into skin and tissue. The idea of a simple and compact piezoelectric powered needle free injector (NFI) is introduced in this article, which offers electric control of injection volume in microliters. An impulse of up to 3500 N-s or more is generated by the multilayer piezoelectric actuator to drive the needle-free injector. The governing equations for the force and mass balance over the syringe plunger were derived to represent the driving mechanism for a compact needlefree injector. Furthermore, simulation was carried out to witness the effect of variation in parameters like impulse force, nozzle diameter and nozzle length on the injection dynamics, and the results prove the dependence of injection characteristics on aforementioned parameters, respectively. Finally, the specifications for fabrication of 10 μl volume delivering piezoelectric-impulse driven needle-free injector were obtained through analysis of multiple simulation results.