Manipulation of liquid marbles

A liquid marble is a liquid droplet coated with hydrophobic powder which enables the marble to be manipulated like a soft solid. Recently, liquid marbles have been used in applications such as microbioreactors for three-dimensional cell cultures and could be a new platform for digital microfluidics. Despite its potential significance, there is a lack of a systematic, thorough review and discussion on the manipulation schemes for liquid marbles. This paper presents past and recent manipulation schemes for liquid marbles. This paper discusses the major working principles, their advantages and drawbacks. Finally, the paper concludes with recent applications and the challenges of this research area.