Picking up and placing a liquid marble using dielectrophoresis

A liquid marble is a droplet coated with hydrophobic powder. The porous and hydrophobic coating prevents physical contact between the liquid and its surroundings without compromising gas exchange. As such, the liquid marble is an excellent platform for culturing cells. With the promising biomedical applications of the liquid marble, numerous studies have been conducted to improve its handling using magnetism, which limits the liquid marble coating to hydrophobised ferromagnetic materials. In this paper, we propose a novel, simple and cheap method of liquid marble manipulation such as pick and place based on the well-known dielectrophoresis force. Liquid marbles of various volumes were picked up using an electrode with a high voltage bias, moved to a different location and placed intact. This method provides reliable handling to a host of existing non-ferromagnetic liquid marbles without the need to engineer their coatings. Furthermore, this method enables the automation of the liquid marble handling process. This paper provides an empirical relationship to link the pickup force to the experimental parameters.