The aim of the invention is to use core materials in inductive coupling systems for the subcutaneous transfer of energy or data, which exhibit great flexibility in their coil systems and increase effectivity. This is achieved by an inductive coupling, consisting of a primary coil system and a secondary coil system, which are combined with core materials. Said coupling is characterised in that a flexible gel-type or encapsulated liquid material is used as the core material of at least one of the coil systems, said material containing dispersed magnetic nanoparticles. |