Dynamic Modeling of Three-Flagellated Swimming Microrobot with Prokaryotic Biologic Propulsion

Micro-Electro-Mechanical Systems (MEMS) technology is creating revolutionary changes particularly in medicine. Swimming microrobots can be specified as a kind of miniature biomedical robots which are designed and fabricated applying this technology. In this paper, inspired by microorganism's motion in nature, a three degree-of-freedom flagellar swimming microrobot is introduced and its three-dimensional motion is dynamically modeled. In our design, the body of the swimming microrobot is driven by multiple prokaryotic flagella which rotate in a fluid media and produce propulsion forces. Due to the small size and low velocity of swimming microrobots, their motion occurs in a very low Reynolds number (Re≪1) fluid flow. Therefore, the inertial forces are less significant compared to viscous forces. Resistive force theory (RFT) is applied to determine the propulsion force which is created by each flagellum. Based on the RFT theorem, the components of the viscous hydrodynamic force are calculated through resistive force coefficients and local velocities of flagellar. Simulation results show that by use of the three flagella the microrobot enables to do three-dimensional maneuvers.