Magnetic Colloidal Micropumps

Presented here are three designs and early prototypes for a mechanical micropump which is actuated by colloidal magnetic micro-spheres controlled by stray fields of magnetic micro-disks. Advantages of this actuation technique include ease of fabrication, no physical attachments to the device, and the ability to scale to much smaller dimensions. The magnetic field profiles, field gradients, and magnetic forces on microscopic beads have been modeled and calculated. The designs are based on popular micro-pump schemes including peristaltic, rotary, and check-valve pump. Here we have demonstrated the ability to fabricate these devices using lithographic techniques.