Magnetic Nanorobots, Generating Vortexes Inside Nanoliter Droplets for Effective Mixing

Magnetic nanorobots are used as nanometer-size stir bars for rapid stirring inside ultrasmall volumes of fluids. Because of their small size and rapid stirring, they can generate many vortexes inside confined small droplets. It is shown that these vortexes can vigorously churn up large microparticles without destabilizing or moving the droplets. The vortex formation can be easily controlled by tuning the stirring rate of nano stir bars using a simple magnetic stirrer.