Characterization and Modeling of Micro Swimmers With Helical Tails and Cylindrical Heads Inside Circular Channels

Micro swimming robots offer many advantages in biomedical applications, such as delivering potent drugs to specific locations in targeted tissues and organs with limited side effects, conducting surgical operations with minimal damage to healthy tissues, treatment of clogged arteries, and collecting biological samples for diagnostic purposes. Reliable navigation techniques for micro swimmers need to be developed for navigation, positioning, and localization of robots inside the human body in future biomedical applications. In order to develop simple models to estimate trajectories of magnetically actuated micro swimmers blood vessels and other conduits, effects of the channel wall must be understood well. In this study, swimming of one-link robots with helical tails in stationary fluids inside channels is modeled with Stokes equations and solved numerically with the finite-element method. Lateral and angular velocities of the robot are obtained from force free swimming conditions. Effects of the amplitude and number of helical waves, and the relative size of the body of the swimmer and its radial position on angular and linear velocity vectors of the swimmer are presented.