Piezoelectric driven self-circulation micromixer with high frequency vibration

Abstract

Active micromixers have been widely used in chemistry, biomedicine and many micro analyses as it offers low reagent consumption, controllable mixing process, safe, and reliable. Based on piezoelectric (PZT) drive technology and numerical simulation results, a self-circulation micromixer with high frequency vibration has been designed and fabricated. The micromixer is composed of PZT micropump, vibration substrate, mixing pool with double U-shaped inlet and outlet, upper cover plate and lower substrate. The performance of the micromixer’s self-circulation and high frequency vibration is evaluated by experimental tests. Experimental results show that: When the drive voltage and frequency of the self-circulation reflux micropump are set to 100 V and 100 Hz, respectively, a significant vortex flow is generated in the mixing pool, and the vortex flow speed is as high as 320 r min−1. When the driving frequency of the vibration substrate is set to its first resonance frequency, the displacement of its center point is the largest up to 28.1 µm. Furthermore, the vortex flow speed of the fluid in the mixing pool and the vibration intensity of the vibration substrate can be adjusted separately by regulating the driving voltage of the PZT micropump and vibration substrate.