Add to ORKGCreating good mixing flows in lab-on-chip systems poses a special challenge, due to the impossibility to generate turbulence. We propose a novel concept for active mixing, that is inspired by nature, namely micro-organisms that swim through a liquid by beating microscopic hairs, cilia, covering their surface. We have fabricated artificial cilia, based on electro-statically actuated polymer structures, and have integrated these in a micro-fluidic channel. Flow visualization experiments show that our cilia can generate very efficient mixing. Since the artificial cilia can be actively controlled using an electrical signal, they have exciting applications in micro-fluidic devices.</p