This letter investigates the link efficiencies and ensuing biohazards when capacitive versus inductive coupling is used to power biomedical implants electromagnetically. Electromagnetic simulations illustrate that the power link efficiency of capacitive coupling decays slower as a function of the distance between plates compared to inductive coupling. Specifically, the case designs show that, using a transmitted power of 1 W at 5 MHz, capacitive coupling produces a 10-g averaged SAR value of 1.63 W/kg compared to 2.39 W/kg for an inductive coupling of the same dimension.
Al-Kalbani, A. I. S., Yuce, M., & Redoute, J-M. (2014). A biosafety comparison between capacitive and inductive coupling in biomedical implants. IEEE Antennas and Wireless Propagation Letters, 13, 1168-1171. https://doi.org/10.1109/LAWP.2014.2328375