Accumulation of Air Bubbles In Field Driven Oscillations of a Droplet

Due to the lack of gravity, the removal of bubbles formed in a flowing fluid presents a challenge in space applications. Existing methods of the bubble separation in lab-on-a-chip systems appear to be of limited use for space applications due to different functional requirements. We present a new method for the field and flow driven concentration and removal of bubbles from droplets of aqueous polymer solutions. A fluid droplet is placed on an electrically insulating film and serves as a floating electrode capacitively coupled to external electrodes. Following the application of alternating current voltage, bubbles accumulate on the drop surface. A voltage pulse is then applied to remove part of drop enriched with bubbles.

The work is supported by NASA grant NNX09AK06G.