Magnetic Driven Wireless Multiple Capsule Robots with Different Structures

Abstract

Magnetic driven microrobots, which travel in water or other aqueous mediums, have provided great potential and are urgently demanded in the biomedical field. Many advances in the self-propulsion mechanism suggest that these small robots are very suitable for using in channels. However, the spatial limitations of the internal environment and the size constraint of the millimeter robots are huge challenges in the medical applications. In this paper, a driven approach for multiple capsule robots with screw structure and propeller structure is explored. The two robots can be controlled by a rotational electromagnetic field generated by two pairs of three-axis Helmholtz coils. Mechanical model is set and hydrodynamics of multiple capsule robots is analyzed. Based on the nonoverlapping driven frequencies, these robots are able to set off at different start frequencies and stop at different step-out frequencies. The verified experiments are conducted in pipe filled with water. Different movements such as docking and release are verified. The experimental results indicate that the multiple capsule robots would be a promising way to accomplish multifunctional manipulation and perform complex surgeries.