Electro-thermal actuated micromixer with VU/VIU/VUVIU/VIUVU patterned microgrooves

The effect of various patterned micro-grooved floors on the mixing efficiency in an AC electro-thermal (ACET) actuated micromixer is studied thoroughly. The patterns such as VU, VIU, VUVIU and VIUVU with different heights are considered for the analysis. Asymmetric electrode pairs are attached to the grooved surface to generate the ACET induced flow. At the same time, the symmetric electrode pairs are inserted on the top wall to enhance the mixing process. The potential at asymmetric and symmetric electrode pairs has been tuned in the range of 3-8 V and 0-10 V to modulate the flow for achieving better mixing efficiency and a higher flow rate. It is found that a mixing efficiency of 0.98 has been achieved for all types of microgrooves when the AC electric potential at the lower electrode pairs is less than 4 V and at the upper electrode pairs is more than 8 V. When the potential at the lower electrode pairs is increased to 8 V, mixing efficiency is found to be reduced and a maximum value is observed to be 0.60 in case of the VIUVU groove. The pumping in the VU groove is better, resulting in a higher flow rate, almost two times more than the others. Mixing efficiency is marginally more for the VU groove with a shorter height; however, it contradicts with other grooves.