Metachronal beating of magnetic cilia

Naturally occurring hair like cilia beat in a metachronal fashion which appears as travelling waves on ciliated surfaces. Such motion is known to facilitate the fluid and particle transport. We design artificial magnetic cilia that mimic metachronal motion of natural cilia. To create metachronal motion, it is essential to impose a phase difference between beating cycles of neighboring cilia within a ciliary array. Such phase difference can be achieved by either applying different forcing to each cilium or by having cilia with different responses to a uniform forcing applied to the entire array. We demonstrate both these approaches to achieve metachronal motion in arrays of magnetic cilia.