School of Mechanical Engineering Seminar
Wednesday, January 16, 2012 at 15:00
Wolfson Building of Mechanical Engineering, Room 206

A Novel Piezoelectric Micropump

Ori Ehrenberg

MSc Student of Dr. Gabor Kosa

One of the major applications of micro fabrication technologies and MEMS are micro fluidics. The driving elements in these micro systems are the micropumps. Micropumps are developed since the 80s and there is vast literature on different pumping methods and several commercial products. The micropumps applications can be found in many fields, among them microelectronic cooling, Lab-on-a-chip, drug delivery, inkjet and more. For each application different performance of the pump is crucial.

Our pumping method is based on a traveling wave actuated in a piezoelectric structure. An electrode wrapping a piezoelectric tube is divided into six segments, two segments at the perimeter direction and three in the longitude direction. By applying them the same frequency voltage with different amplitude and phase, a traveling wave is produced and the flow inside the tube is initiated. Another embodiment of this method is based on two parallel beams.

We solve analytically a multi-physics model that links the piezoelectric beam's vibration with low Reynolds number hydrodynamics. The micropump we developed is advantageous in high flow rate low volume requirement applications. From theoretical model we found that a two-beams micropump with a 15X2X0.3 mm beam actuator have a volume of 138 mm  is capable creating a flow of 3200 μl/min which is 5 time higher volume to flow ratio compared to other micropumps in development.

In addition from the first prototypes we built, we were able to achieve flow rates in the order of 10 μl/min using a two beams micropump with a beam actuator of 35X2.5X0.7 mm.