Novel 3D magnetic tweezer system for microswimmer manipulations

Microrobots have an enormous potential in medical applications such as the minimal invasion to human body, drug delivery and drug imaging. Magnetic tweezers, as a very powerful tool in micro manipulation, has been investigated by many researchers. However, most of the previous researches mainly have utilized the magnetic tweezer on very small working space with two-dimensional control inputs. This paper discusses the design and implementation of a 3D magnetic tweezer system with a wide working range to manipulate microswimmers, which are assembled with different amount of microbeads, by utilizing magnetic forces created from magnetic field gradient. Experiments performed using our designed magnetic tweezer demonstrate the manipulating of microswimmers in order to follow the desired trajectories, speed control and swarm motion. We prove that the suggested magnetic tweezer has enough power and the controllability to manipulate microswimmers in Newtonian fluid environments. Even though we had the limited development of software level control method at present state, it is available to perform agile and relatively accurate moving behaviors using manual control method.