J024023 A Study on Spiral Motion of Microbe's Flagellum Based on Model Experiment and Stoke's Theory

Abstract

Microbe can move smoothly in water environment with high efficiency, which could offer new ideas for future micro machines. In this study, we investigated the spiral moving behavior of flagellum by using Stoke's theory and experimental models. We simulated euglena's fluid environment of Re number of 10^<-4>. The optimal spiral shapes in terms of propulsive efficiency and the comparison with Stoke's theory were studied. The propulsive efficiency was found to be highest when the spiral diameter was 15mm or 20mm as a result of the tradeoff between torque and propulsive force. From real motion of euglena, the drag force the body receives was estimated and converted to the value what the model experiment gave as propulsion force. We found that the model experiment gave enough and meaningful force to drive the whole body.