How to capture active Marangoni surfers

Abstract

Surfers at the air-water interface form a large subset of the domain of active matter systems. They range from the water strider in the biological world to the soluto-capillary effect...

Can self-propelled objects escape from compression stimulation?

“…Based on the experimental results and related reports, [19][20][21][22][23][24][25][26][27][28][29][30][31][32] we discuss the mechanism of escape from C in to C out for two types of self-propelled objects: CPs and MCPs. Here, the time required for N out to reach 4 as the equilibrium condition is defined as the relaxation time, t e .…”

“…4 and 5 suggest that the difference in surface tension between C in and C out enhances the escape of CPs from C in to C out because CPs move in the direction of higher surface tension. 23,26,[30][31][32] We assume that the time variation of N out is expressed by eqn (1). Here, we ignored the repulsive and attractive forces between self-propelled objects and their volume.…”

“…4 and 5 suggest that the difference in surface tension between C in and C out enhances the escape of CPs from C in to C out because CPs move in the direction of higher surface tension. 23,26,30–32…”

The motion of micro-swimmers over a cavity in a micro-channel

“…Secchi et al 45 proved that the local flow generated by the curved surface would attach bacteria to the surface, achieving the induced capture of bacteria in the flow. Tiwari et al 46 used a micro-air pump to disturb the air–water interface locally and change the surface tension, creating a local attraction area to capture soluto-capillary effect-driven interfacial surfers. The motion behaviour of micro-swimmers in micro-tube constructions with micro-cavities, prevalent in daily production and life, is particularly neglected in the pertinent study.…”