The purpose of this research was to investigate inductive coupling as a way to wirelessly power electronic devices dispersed in water. The most important parameters determining this efficiency are: (1) the coupling between transmitting and receiving coils, (2) the quality factors of the transmitting and receiving coils, (3) the number of receiving coils and (4) the matching of the receiving coil with the load. Experimentally we showed that 1 transmitting coil can wirelessly power 18 or more receiving coils dispersed in water with an efficiency higher than 75%. Compared to vacuum or air, water as the core material of the transmitting coil has a negative influence on the quality factor by increasing the turn to core parasitic capacitance and lowering the self resonance frequency of the transmitting coil. The results demonstrate a promising way to wirelessly power electronic devices, e.g. UV-LEDs, ultrasound transducers, electrodes and sensors, and that inductive coupling can be used in new, innovative designs for water treatment and related process technologies.
Kuipers, J., Bruning, H., Bakker, S., & Rijnaarts, H. H. M. (2012). Near field resonant inductive coupling to power electronic devices dispersed in water. Sensors and Actuators. A: Physical, 178, 217-222. https://doi.org/10.1016/j.sna.2012.01.008