Pumping of Ionic Liquids by Liquid Metal-Enabled Electrocapillary Flow under DC-Biased AC Forcing

A novel method is proposed to pump room-temperature ionic liquids (ILs) by making use of liquid-metal-enabled electrocapillary flow driven by a DC-biased AC forcing. The effectiveness of this pump strategy is demonstrated by both numerical simulation and experimental observation considering multiple frequency electrochemical polarization. The device can work practically in a wide range of different parameters, such as DC bias, AC voltage amplitude, the shape of the waveform, as well as the electrode separation. Though liquid metal (LM) has already been reported to help deliver the traditional sample of high-conductivity aqueous electrolytes, its adaptability to drive ILs has apparent advantages, such as quicker pump flow rate due to greater initial interfacial ion adsorption, and much longer operating life due to its nonvolatile feature. The results prove invaluable for the elaborate construction of flexible electrokinetic platforms taking high-speed ILs as the working fluid.