Fully 3D-printed, nonelectric, spring-powered syringe pump for operating microfluidic devices

Microfluidic devices require a precise and steady flow for fluid control. The high demand for microfluidics in point-of-care testing (POCT) necessitates a portable, low-cost, and electricity-free pumping method for operating microfluidic platforms in low-resource settings. This study presents a fully 3D-printed and portable syringe pump operated by torque from a flat spiral spring. The syringe pump can be operated by manually winding up the spring, and various flow rates can be obtained using different syringe sizes and selecting appropriate gear combinations. It generated a steady flow rate ranging from 1.4 µL/min to 12.0 µL/min with high repeatability. The pump is suitable for the on-site use of microfluidic platforms because it does not require electricity and does not occupy a large space. The 3D printed pump proposed in this study is named precise, rapid-prototyped, nonelectric, torque-driven (PRNTD) pump. The versatility and utility of the pump are demonstrated by generating a linear concentration gradient using a microfluidic gradient generator and microdroplets using a T-channel microfluidic chip. The PRNTD pump can facilitate the on-site application of microfluidic platforms in resource-limited settings and contribute to the widespread use of microfluidic technologies.