Resistive force theory based modeling and simulation of surface contact for swimming helical micro robots with channel flow

Possible uses of bio inspired swimming micro robotics devices in confined viscous domains constitutes the need for real-time models with the capability of predicting the problem of contact with solid boundaries of varying stiffness. The model presented in this paper incorporates known numerical and analytical solutions to various problems and proposes an alternative tool to handle hydrodynamics and rigid body kinematics of the motility of bacteria and bio-inspired swimmers in viscous channels. Presented three-dimensional trajectory examples are solved by means of resistive force theory (RFT) based equation of motion with simple forward Euler integration. It is demonstrated that the effects of channel flow, gravity, lubrication, and contact stiffness with structural damping can be studied coupled with a six-degrees-of-freedom time dependent robotic model using quaternion rotations to handle rigid-body rotations. Trajectory studies indicate that the structural stiffness term should be significantly smaller than the damping term in order to prevent sudden local jumps.