Dynamics modeling and analysis of a swimming microrobot for controlled drug delivery

The design of a tiny swimming robot, which is composed of a spiral-type head and an elastic tail, is proposed in this paper. The microrobot is designed for controlled drug delivery as well as a wide range of biomedical applications. It is at the millimeter scale and suitable for swimming under low Reynolds number (Re) environment. The head part of the swimming robot is driven by external rotating magnetic fields, which enables it to be operated wirelessly. The spiral-type head accommodates communication and control units and serves as the base for the elastic tail. When a rotating magnetic field is applied, the head rotates synchronously with the field, generating and propagating driving torque to the straight elastic tail. When the driving torque reaches a threshold, dramatic deformation takes place on the elastic tail. The tail then transforms into a helix and generates helpful propulsive thrust. The entire tail also serves as a drug reservoir in controlled drug delivery operations. This paper´s focus is to analyze the dynamics of the microrobot using resistive force theory (RFT), and compare the propulsion performance with other rigid-body microrobots