Flow characterization in micromixer with actuation

Abstract

This project presents an investigation on flow characterization in a micromixer with actuation. The micromixer consists of a microchamber and microchannels together with a build-in piezoelectric (PZT) disk actuator. The mixing enhancement is produced by inducing vortices inside the micromixer. Two different designs of micromixer are studied, the nozzle-shape chamber and the circle-shape chamber.

Lamination technology was used to fabricate the micromixer where a spacer made of dry adhesive layer was sandwiched between two thick Polymethylmethacrylate (PMMA) layers. Both the designs were driven by PZT disk which served as an actuator, together with three plastic nozzles which were attached to the two inlets and one outlet.

Experiments were carried out using two different kinds of fluids, DI water and DI water-glycerol solutions. To conduct flow visualization of the flow fields and patterns under various actuations, a high speed camera system coupled with Phantom Camera Control (PCC) software were used.

The results show that the design of the nozzle-shape chamber has a higher overall mixing efficiency and wider actuation frequency window than the circle-shape chamber, in terms of actuation voltages and driving frequencies when DI water is used as the working fluid.