Design and Experiment of 2D Rectangular Solenoid Transmitting Coil for Novel Gastrointestinal Capsule Robot

A two-dimensional rectangular solenoid transmitting coil is proposed to address the problem that the three-dimensional receiving coil occupies excessive space inside the capsule robot. The transmitting coil consists of two pairs of rectangular solenoid coils distributed radially along the human body. By changing the direction of current flow, it can generate a two-dimensional magnetic field covering the whole central plane. Firstly, the working mechanism of the wireless power transfer system is introduced, and then the spatial electromagnetic field generated by the transmitting coil is analyzed through both mathematical calculations and finite element simulations. Finally, an experimental platform is built to determine the optimal resonant frequency of the system and validate its feasibility based on the power transfer efficiency and the receiving power. The experimental results demonstrate that when the receiving coil is located at the center of the coil pair, the receiving power is 1 416mW and the power transfer efficiency is 3.96%. Additionally, when the receiving coil operates in the central plane, it can receive sufficient energy regardless of the orientation.