Precisely manipulating small amounts of liquids has been widely applied in industry

ranging from biomedical devices to liquid transfer.Currently

direct light-driven manipulation of liquids

especially those triggered by light-induced capillary forces has drawn an increasing attention

because it requires neither special optical set-up nor complex microfabrication steps.However

the capillary force arising from wettability gradient is too small to overcome the effect of contact line pinning

and the motion is thus limited to specific liquids with a relatively short distance

simple linear trajectories

and low speed

Here

Yu

et al.

at Fudan University reported a new strategy to precisely manipulate liquids by photo-induced asymmetric deformation of tubular microactuators

which is a novel principle to induce capillary forces.These microactuators exhibit the unique capabilities to propel a wide diversity of liquids over a long distance with desirable velocity and controllable direction.Application in areas such as micro-opto-mechanical systems and optofluidics is highly anticipated.