Critical Trapping Conditions for Floating Liquid Marbles

Floating liquid marbles, small nonwetting liquid droplets encapsulated by fine hydrophobic powder located on a free liquid surface, can serve as a unique microbioreactor platform. Trapping and positioning of these liquid marbles are essential for efficient sample handling. We investigate the dielectrophoretic trapping process of floating liquid marbles that are moving on a free water surface. The dynamic behavior of the trapping process is analyzed experimentally and theoretically. More importantly, a governing equation describing successful trapping is generalized from the energy balance. This study facilitates insights into dielectrophoretic manipulation of liquid marbles and fills the gap of knowledge in handling small soft systems.