Manipulating thermocapillary migration via superoleophobic surfaces with wedge shaped superoleophilic grooves.

Hypothesis: Thermocapillary migration is a phenomenon that liquid droplets can move from warm to cold regions on a nonuniformly heated surface. We expect to construct functional surfaces to manipulate the migration of liquid lubricants on rubbing surfaces.

Experiments: Superoleophobic surfaces with wedge shaped superoleophilic grooves of varying geometrical parameters are fabricated, and migration experiments of typical liquid lubricants are performed on the designed surfaces.

Findings: Manipulation capacity of the designed surfaces on the migration of liquid lubricants is confirmed, and the mechanism is revealed. An effective method using superoleophobic surfaces with wedge shaped superoleophilic grooves to reconcentrate the migrated lubricants is highlighted. Moreover, a general design philosophy for patterns of wedge shaped groove is proposed.