METHOD AND APPARATUS FOR MAGNETIC MIXING IN MICRON SIZE DROPLETS

摘要

Active mixing by magnetic stirring is demonstrated inside a picoliter-size liquid droplet. Magnetic microspheres are added to the droplet, which form aligned chains under the influence of a homogeneous magnetic field. When the magnetic field is rotated, the chains also rotate synchronously. Viscous interaction between the particle-chains and the liquid induces advective motion inside the droplet thereby enhancing mixing which is otherwise diffusion-limited. The concept can be effectively used to create a lab-in-a-droplet for MEMS (Micro-Electrical-Mechanical Systems) and Bio-MEMS applications.