ALL POLYMER 3D PRINTED PUSH/PULL SYRINGE PUMP FOR ENHANCED FLOW CONTROL

Syringe pumps are high-precision devices designed to deliver precise volumes of fluids at a constant flow rate, essential for many microfluidic applications.In this study, we present the development of a novel, affordable and innovative push-pull type syringe pump, constructed using rapid prototyping techniques, including 3D printing and laser cutting.The device is engineered to perform simultaneous infusion and withdrawal of fluids at constant flow rates in parallel and identical syringes.To achieve this, a dual rack and single-pinion mechanism was employed to yield a linear motion in the 3D printed components.The simple and compact design with syringes oriented in the same direction allows for the use of very short tubing unlike other commercially available pumps (e.g., Drifton, LP-LSP01-1C) which use opposite-facing syringe configuration.All 3D printed components of the syringe pump were designed in Autodesk Fusion 360 and printed with an Ender 3 v2 3D printer as shown in fig 1.The syringe pump's housing was fabricated using 5 mm PMMA sheets.The CAD design of the complete assembly of the pump is shown in fig 2 .A Sensirion SLF3S-600 liquid flowrate sensor evaluation kit, with an operational range of 0-2000 l/min was integrated to control and monitor the flow rates.Additionally, the electronic system consisted of three main circuits: safety circuits with multiple redundancies, a stepper motor driving circuit and a sensor circuit.A user-friendly graphical interface was also designed and integrated (fig.3).We report this syringe pump as an impactful advancement over conventional syringe pumps which operate on the leadscrew mechanism, converting rotational motion into linear motion using a stepper motor.Despite providing precise and extremely low flow rates, these pumps are expensive, bulky, require regular maintenance and calibration, consume high power, and produce operational heat and noise.Apart from these limitations, they also pose significant challenges in microfluidic applications, such as pulsatile flow at lower flow rates which builds air pockets, mechanical backlash and hysteresis, delay in response upon changes in flow rate, and synchronization issues in multi-channel systems.