title: Self-assembled artificial cilia.
abstract: Due to their small dimensions, microfluidic devices operate in the low Reynolds number regime. In this case, the hydrodynamics is governed by the viscosity rather than inertia and special elements have to be introduced into the system for mixing and pumping of fluids. Here we report on the realization of an effective pumping device that mimics a ciliated surface and imitates its motion to generate fluid flow. The artificial biomimetic cilia are constructed as long chains of spherical superparamagnetic particles, which self-assemble in an external magnetic field. Magnetic field is also used to actuate the cilia in a simple nonreciprocal manner, resulting in a fluid flow. We prove the concept by measuring the velocity of a cilia-pumped fluid as a function of height above the ciliated surface and investigate the influence of the beating asymmetry on the pumping performance. A numerical simulation was carried out that successfully reproduced the experimentally obtained data.
authors.affiliation: J Stefan Institute, Jamova 39, 1000 Ljubljana, Slovenia. mojca.vilfan@ijs.si
authors.forename: Mojca
authors.initials: M
authors.lastname: Vilfan
authors.forename: Anton
authors.initials: A
authors.lastname: Potocnik
authors.forename: Blaz
authors.initials: B
authors.lastname: Kavcic
authors.forename: Natan
authors.initials: N
authors.lastname: Osterman
authors.forename: Igor
authors.initials: I
authors.lastname: Poberaj
authors.forename: Andrej
authors.initials: A
authors.lastname: Vilfan
authors.forename: Dusan
authors.initials: D
authors.lastname: Babic
mesh_terms: D057005:Bioengineering; D055592:Biophysical Phenomena; D002923:Cilia / Q000502:physiology*; D003102:Colloids; D004867:Equipment Design; D008280:Magnetics; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation*; D008962:Models, Theoretical; D012212:Rheology
chemical_list: D003102:Colloids