The Effect of Different Monolithically Integrated Check Valve Designs on the Efficiency of Disposable PZT-PDMS-Micropumps

In the presented study, check valve micropumps with three different valve designs have been developed, fabricated, and successfully tested. These check valves — in the form of differently shaped flaps — were integrated monolithically within the microchannel inlet and outlet of the pump chamber which allows for rapid and inexpensive fabrication of the device. The pump is made of Polydimethylsiloxane (PDMS) with a fully integrated circular piezo-electric transducer (PZT) as a micropump actuator. The performance of the micropumps was characterized under different actuator frequencies, depending on the excitation signal (square, sinusoidal or saw tooth), the implemented PZT diameter (10 mm or 15 mm), as well as the applied offset voltage (positive or negative). Ethanol was used as the working fluid in all experiments. The fabrication technology of the monolithically designed micropump is described, and the results are presented in terms of flow rates. The presented work suggests that the check valve design has an apparent effect on the micropump performance under different operational conditions. All in all, the first results show promising characteristics for easy and inexpensive integration of the proposed micropump in disposable lab-on-a-chip systems.