Elasticity-driven droplet movement on a microbeam with gradient stiffness: a biomimetic self-propelling mechanism.

Directional movement of liquid droplets is of significance not only for certain physiological processes in nature but also for design of some microfluidic devices. In this study, we report a novel way to drive directional movement of liquid droplets on a microbeam with a varying or gradient stiffness. We use the energy method to theoretically analyze the interaction between a droplet and the elastic microbeam.