title: Bubble-free electrokinetic flow with propylene carbonate.
abstract: For electroosmotic pumping, a large direct-current (DC) electric field (10+ V/cm) is applied across a liquid, typically an aqueous electrolyte. At these high voltages, water undergoes electrolysis to form hydrogen and oxygen, generating bubbles that can block the electrodes, cause pressure fluctuations, and lead to pump failure. The requirement to manage these gases constrains system designs. This article presents an alternative polar liquid for DC electrokinetic pumping, propylene carbonate (PC), which remains free of bubbles up to at least 10 kV/cm. This offers the opportunity to create electrokinetic devices in closed configurations, which we demonstrate with a fully sealed microfluidic hydraulic actuator. Furthermore, the electroosmotic velocity of PC is similar to that of water in PDMS microchannels. Thus, water could be substituted by PC in existing electroosmotic pumps.
authors.affiliation: Department of Mechanical Engineering, University of Maryland, College Park, MD, USA.
authors.forename: Deepa
authors.initials: D
authors.lastname: Sritharan
authors.affiliation: Department of Mechanical Engineering, University of Maryland, College Park, MD, USA.
authors.forename: Abraham Simpson
authors.initials: AS
authors.lastname: Chen
authors.affiliation: Department of Mechanical Engineering, University of Maryland, College Park, MD, USA.
authors.forename: Prabhath
authors.initials: P
authors.lastname: Aluthgama
authors.affiliation: Department of Bioengineering, University of Maryland, College Park, MD, USA.
authors.forename: Bilal
authors.initials: B
authors.lastname: Naved
authors.affiliation: Department of Mechanical Engineering, University of Maryland, College Park, MD, USA.|Institute for Systems Research, University of Maryland, College Park, MD, USA.
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Smela
mesh_terms: D004566:Electrodes; D053841:Electroosmosis / Q000295:instrumentation*; D004867:Equipment Design; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation* / Q000379:methods; D011407:Propane / Q000031:analogs & derivatives* / Q000737:chemistry; D012371:Robotics / Q000295:instrumentation*
chemical_list: C045990:propylene carbonate; D011407:Propane
keywords: Electroconjugate flow; Electrolytic degradation; Microfluidic; Soft lithography; Soft robotics