Performance evaluation of the wireless microrobot in pipe with symmetrical spiral structure

A wireless microrobot may be used in the small space and biomedical practice, especially in the industrial field and biomedical application. In this paper, we designed a new kind of wireless microrobot with symmetrical spiral structure, which have more compact volume, completely symmetrical mechanical structure, quick response, forward-backward motions and can clean the dirt adhering to the inner wall. According to the hydromechanical lubrication theory and Newton viscous law, we build the motion model of the microrobot. Through analysis, simulations and experiments, this paper had evaluated the effect of spiral depth and thread unit number. In addition, we verified the feasibility of this new kind of microrobots, and obtained the moving speeds of forward-backward and upward-downward motion in the pipe. The experimental results indicated that the maximum moving speed is 22.68 mm/s at 12 Hz in the horizontal direction and 6.29 mm/s at 13Hz in the vertical direction with input currents of 0.7A. Finally, we designed a control panel for this system, which can control the microrobot current motion states easily, and make our system more portable and compact. The designed wireless microrobot can move smoothly in water and other liquid medium and is very useful in the industrial application and microsurgery application.