The Swiss Federal Institute of Technology in Lausanne (École Polytechnique Fédérale de Lausanne, EPFL) is a renowned university well known for their scientific work. The Institute of Microelectronics and Microsystems (IMM), part of EPFL, is doing research in the fields of microelectronics, microsystems and nanotechnology.

Some research document features small E-cores in 3F3 and several Ferroxcube NiZn ferrites, obtained from thin ferrite plates by powder-blasting. They were chosen to investigate the high-frequency properties (L and Q up to 3 GHz) of hybrid flex foil inductors.



Fig a : SEM photograph of the smallest microstructured single ferrite E-core (2 x 0.71 x 0.5 mm).
Fig b : A final assembled inductor.

See the below link to the research report of M. Saidani and M.A.M. Gijs :

Hybrid flex foil ferrite technology for miniaturized power and RF applications (3F3 in chapter 3 and NiZn in chapter 4)