Motion dynamics of liquid drops and powder-encapsulated liquid marbles on an inclined solid surface

Nowadays, superhydrophobicity has been the limelight of the academic community owing to the plethora of applications. In this work, the downhill motion of liquid drops and liquid marbles was investigated by two distinct particle-laden interfaces. Liquid drops and liquid marbles accelerate firstly and then move on the slope with a steady velocity which decreases with the liquid viscosity. The steady velocity of liquid marbles is lower than that of liquid drops while the maximum aspect ratio of liquid marbles is higher than that of liquid drops, due to different interface interactions. The particles on the solid substrate enhance the motion of liquid drops while those on the liquid surface reduce the surface tension of liquid marbles. Both liquid drops on non-stick solid surface and non-stick liquid marbles on solid substrate could provide theoretical basis for the precisely targeted transportation of small quantities of liquids by particle-laden interfaces, especially in chemical and biomedical applications.