3D wireless power transfer based on 3D printed electronics

In the past decade, wireless power transfer enabled many new applications. However, most designs of transmitter and receiver coils are 2D, which limits the possibilities of integrating them to more applications. In this paper, based on the Qi standard, we proposed a design of 3D coils by focusing on the 3D geometry of the coil, modelling, simulation and manufacturing. Using the 3D spiral transmitter coil and the receiver coil as an example, we present the mathematical model for WPT first. The performance of the model is then verified by FEM simulation. Three sets of 3D coils with different design parameters were prototyped by 3D printed electronics and measured against the model and the simulation results. Compared to the measurements, the model has average errors of 1.6%, 8.4% 8.5% regarding self-inductance, mutual-inductance and the coupling factor, where the simulation has average errors of 0.5%, 9.9% and 6.6%, respectively. Measurements also indicate that with a 5V input, the prototype is able to deliver 1-watt power at an average 20.5% efficiency without electromagnetic shielding. It was concluded that the proposed 3D coils designs are feasible and promising for WPT.