(182c) Electro-Hydrodynamic Behavior of Soft Liquid Metal Plugs Under Low Voltages
- Conference: AIChE Annual Meeting
- Year: 2017
- Proceeding: 2017 Annual Meeting
- Group: 2017 Annual Meeting of the AES Electrophoresis Society
- Time: Monday, October 30, 2017 - 1:45pm-2:00pm
In this work, we utilize low voltages (<2 V) to reversibly move droplets of EGaIn through microchannels. Pre-wetting the channels with an aqueous solution prior to injecting the metal prevents oxide adhesion; the water forms an interfacial âslip-layerâ the metal and channel wall. Thereafter, an applied electric field (~10-20 V/m) actuates the liquid metal by establishing a gradient of surface tension; this effect is known as continuous electrowetting (CEW). Although CEW has been utilized before with mercury, which is toxic, the adhesive nature of the Ga oxide complicates CEW behavior. This work utilizes optical microscopy, cyclic voltammetry, and electrochemical impedance spectroscopy (EIS) to characterize electro-hydrodynamics of the system under a variety of conditions. Specifically, we elucidate the influence of electrolyte (i.e., composition, pH, and viscosity) on the metal-electrolyte interface. In addition, we compare electro-hydrodynamic behavior of EGaIn with and without the presence of an oxide âskin.â Finally, this work explores novel microfabrication strategies to design interfaces that prevent oxide adhesion.