Dynamics of High-Flux Capillary Pump

The structure and arrangement of the micropillar array in the micropillar capillary pump have a significant influence on its flow resistance and flow rate. Therefore, research and prediction of the conveying performance can provide valuable guidance for the design of the capillary pump. In this study, we designed a high-flux capillary pump using large-sized micropillars. The flow rate and resistance of the pump were investigated through numerical simulations under various arrangement patterns, with a fixed column height of 0.4 mm and minor axis lengths ranging from 0.1 to 0.75 mm. It is found that the performance of the capillary pump is different when the shape or arrangement of the micropillars is changed. Considering the resistance and flow rate, the pumping effect of rhomboid micropillars is the best. Compared with the capillary pump with low height and small-sized capillary columns, the flow resistance of the pump is small, and the flux can be increased by dozens of times, but the side friction resistance and front form drag between the fluid and the micropillars cannot be ignored. In this study, the dynamic formula considering the side friction resistance is derived, and the resistance prediction formula of the high-flux capillary pump is derived according to the simulation results.