Parabolic Flight: Validation of Electro-Hydrodynamic Gas-Liquid Phase Separation in Microgravity

The lack of the gravity-driven gas-liquid phase separation in microgravity has severely compromised a wide range of space technologies, ranging from liquid pumps to volumetric techniques for sampling liquids and to electrolytic oxygen generators. Even the removal of bubbles growing on surfaces in contact with a liquid presents a challenge in microgravity. Unexpectedly, while carrying out experiments on polarized suspensions in microgravity aboard the NASA aircraft in 2003, we observed the appearance of a gas-liquid phase separation caused by the application of high-gradient electric fields. Based on these observations and supported by a NASA grant, we developed a novel method for the field and flow driven concentration and removal of air bubbles from fluids in microgravity. The proposed method is based on the discovery of collective electro-hydrodynamic (EHD) phenomena in ensemble of bubbles driven by the interplay of electric and hydrodynamic forces.
Abstract (Nov 2013): Electric field driven bubble motion in microgravity
These parabolic flights tested the setup that lead to ISS experiments in this paper. More »