Double acting syringe pump using a rack and pinion mechanism — Simulink model

Continuous and accurate fluid delivery is a real challenge in many of the modern industrial applications such as continuous subcutaneous infusion, micro fluidics, delivery of hydrogel in rapid 3D printing, liquid-liquid micro extraction, etc. In most of the drug delivery systems, drug needs to be injected at a rate even less than a drop per minute. So in order to design such a precise delivery system that ensures continuous flow, there arises a need to employ different mechanisms depending upon the applications. In the present work, rotary to linear converting mechanism using rack and pinion with and without worm wheel for a double acting syringe pump is simulated using Matlab-Simulink toolbox. To have high accuracy in position of the syringe plunger, a 1.8 degree stepper motor is considered as a syringe actuator. The rack and pinion assembly consists of only two members i.e. a toothed rack and a pinion gear. The simulation results show that the designed mechanism is able to deliver the fluid continuously with precise delivery.