Single-Disk and Double-Disk Viscous Micropump

The development and testing of two novel micropumps called the single-disk and double-disk viscous pumps are described. A single disk and the top pump housing, or two disks are separated by a small gap that forms a fluid passage. A wiper, that is the height of this gap, is placed between the two disks, or between the single disk and top pump housing, and extends from the outer diameter of the disk(s) to the center region of the disk(s). The movement of the disk(s) induces viscous stresses on the fluid that forces the fluid through the pump area above the single disk, or between the two disks. The wiper acts to “wipe” the fluid from the disk(s) toward the outlet channel. The fluid flow through the double-disk pump is visualized using a red Rhodamine dye that is injected into the fluid passage upstream of the pumping area. Experimental flow rate for the single-disk and double-disk pumps are obtained for a disk diameter of 2.381 mm, and a gap height of 103 μm. The maximum flow rates obtained are 0.74 ml/min and 2.1 ml/min for the single-disk and double-disk pumps, respectively, for a rotational speed of 5000 rpm. Advantages of the disk pumps include simplicity of design, planar structure, continuous flow, well controlled flow rate, and mixing characteristics.