Abstract: A conical helical microrobot was designed to simulate the execution of complex operations such as targeted drug delivery and vascularization in living organisms. The structure of the conical helical microrobot consists of a cylindrical head,a conical helical tail,and a NdFeB permanent magnet. In order to meet the three-dimensional motion control requirements of the conical helical microrobots in low Reynolds number liquid,a universal rotating magnetic field generator was designed based on the principle of superposition of space vectors,and the magnetic field strength and uniformity of the universal rotating magnetic field generator were optimized by the finite element analysis method. A conical helical microrobot was fabricated and a magnetic drive system was constructed to perform the conical helical microrobot three-dimensional motion control experiments. The experimental results show that the maximum swimming velocity is 1 mm/s for conical helical microrobot in glycerol,which is able to realize stable two-dimensional and three-dimensional motion control as well as complete the complex operation of traversing the maze.

Key words: microrobot, helical structure, universal rotating magnetic field, motion control