title: Syringe-pump-induced fluctuation in all-aqueous microfluidic system implications for flow rate accuracy.
abstract: We report a new method to display the minute fluctuations induced by syringe pumps on microfluidic flows by using a liquid-liquid system with an ultralow interfacial tension. We demonstrate that the stepper motor inside the pump is a source of fluctuations in microfluidic flows by comparing the frequencies of the ripples observed at the interface to that of the pulsation of the stepper motor. We also quantify the fluctuations induced at different flow rates, using syringes of different diameters, and using different syringe pumps with different advancing distances per step. Our work provides a way to predict the frequency of the fluctuation that the driving syringe pump induces on a microfluidic system and suggests that syringe pumps can be a source of fluctuations in microfluidic flows, thus contributing to the polydispersity of the resulting droplets.
authors.affiliation: Department of Mechanical Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong, China. ashum@hku.hk.
authors.forename: Zida
authors.initials: Z
authors.lastname: Li
authors.forename: Sze Yi
authors.initials: SY
authors.lastname: Mak
authors.forename: Alban
authors.initials: A
authors.lastname: Sauret
authors.forename: Ho Cheung
authors.initials: HC
authors.lastname: Shum
mesh_terms: D057446:Hydrodynamics; D007260:Infusion Pumps; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation*; D013594:Syringes; D014732:Vibration; D014867:Water
chemical_list: D014867:Water