Research On The Kinetic Characteristic Of Flagella-like Micro Robot

Swimming micro-robots have great potential in various application domains since they’re tiny and sophisticated enough to reach narrow spaces that are inaccessible to humans and macro-robots to do micro-manipulations. Micro-robots are inspired by the locomotion of microorganisms in the lowReynolds-number flow regime, bionic research of which has become a hot topic in academia. Taken a flagella-like micro-robot as the object of study, the approaches of the theoretical analysis, numerical simulation and experimental measurement are used in this paper for studying its biomimetic mechanism and kinetic characteristic. The main jobs are as follows:Firstly, this paper analyzes the driving mechanism of flagellar microorganisms which is the bionic principle of the swimming micro-robot. By discussing several application examples based on the three most widely used hydrodynamic analysis methods, namely the slender body theory, the resistive force theory and the boundary element method, the article makes a comparison among them. The result shows that the boundary element method is the most precise and applicable one; the slender body theory is suitable for slender body swimmers and has a good accuracy; while the calculation of the resistance theory is the simplest satisfying most applications with not that high accuracy demand.Secondly, a dynamical model for the bacteria in an infinite liquid is established so as to research on the wall-effect of swimming flagella. The numerical results are comparable to the experimental values which verified the validity of the model. Moreover, the relation between the flagellum geometrical parameters, the flagellar rotational rate and its swimming speed variation was calculated. All above researches will provide a reference for the avoidance of surface effects in the motion control of a bio-mimetic swimming robot.After that, the paper presents computational fluid dynamics modeling and analysis of the flow due to the motion of a flagella-like micro-robot with helical tails attached to its body. Time-averaged velocities of the micro-robot are analyzed as functions of rotation frequency and structural parameters of the tails, density and dynamic viscosity of the fluid.Finally, the vision-based experimental platform is established. On the basis of the platform and the image sequence method, the paper conducts the experimental research on the characteristics of the straight movement of the flagella-like micro-robot prototype. The experimental results are in good agreement with the simulation results.