Magnetic Artificial Cilia Carpets for Transport, Mixing, and Directional Diffusion

Natural cilia undertake various roles, such as sensing, propulsion, and transport, in an extensive range of biological systems, and the development of artificial cilia systems has received great attention nowadays. Herein, a multifunctional magnetic artificial cilia carpet (MACC) via a bottom-up template-free approach based on magnetic self-assembly is reported. The in-plane and out-of-plane motion model of the single cilium is established, and then it is expanded to the asynchronous and synchronous collective motion of MACC. Through the cooperation of multi-cilia actuated by an external magnetic field, the MACC exhibits different cilia-inspired collective motion to realize multiple functions, i.e., reverse cargo transport for different-shape objects, linear/circumferential solid mixing based on the asynchronous/synchronous collective motion, and directional diffusion in the viscosity-dominated environment. The proposed MACCs and relevant control strategies deepen the knowledge of the collective motion of artificial cilia systems and broaden their applications for small-scale manipulation and microfluidic devices.