Characteristic evaluation of a magnetic-actuated microrobot in pipe with screw jet motion

Research on capsule robotics has been going on for many years, it has extensively applied to the field of endoscopy. The biggest advantage of capsule robots is that they can be swallowed, move in narrow channels, drug delivery and surgery. However, to make itself be able to move in tight spaces, capsule robot must keep its volume small enough which means it also becomes the biggest challenge of the development of capsule robots. This paper carried out a series of simulations and experiments in order to evaluate the characteristic influence of different structures on motion performance for a magnetic-actuated screw jet microrobot (SJM). The whole system consists of three main parts, the power supply section, three-axes Helmholtz coils are to provide a uniform controllable rotating magnetic field; the simulated intestinal part, a transparent plastic pipe; a screw jet microrobot, it consists a radially magnetized O-ring type neodymium magnet and a rotating screw jet structure. Although we carried out this kind of robot over past few months, it still has a lot of uncertainty on the motion performance. The previous papers have proposed this type of magnetic actuated screw jet microrobot and its driving device, principle, etc., since we proved it can run smoothly (extra degree of freedom that enables various advanced functions such as axial position control). The research in paper consists of three evaluation parts, separately evaluated shell, screw, and different liquid environments. The first part evaluated the inlet and outlet size on the shell section, as for the second part, we evaluated the effect on screw with different pitch. The last part of the experiment is about experimenting different kinds of liquid. We also did the simulations and discussed about the motion performance in order to make sure that our results is realizable before the experiments. Combining the simulation results and experimental results, we will discuss the optimal choice of the design by the simulation in an ideal environment and the comparison of experimental results.