Modeling of mm-sized solenoid coils with ferrite tube core for biomedical implants

Abstract

The sizes of the implanted biomedical devices are required to be millimeter in some applications, which poses a significant challenge for energizing the devices wirelessly. Inserting a ferrite tube into a solenoidal power receiving coil can keep the device compact, compared to the case of inserting a ferrite rod. In this paper, an analytical model of this solenoidal coil is established, based on an analytical effective permeability model of the ferrite tube. This new model is verified by simulation and can be used for designing the wireless power transfer system and optimizing the power transfer efficiency.