The authors have shown the feasibility of using magnetic brushes as a new tool for micro and nanoseparation technology purposes. Magnetic brushes are devices formed by grafting chemically onto a surface a set of nanomagnetic chains by one of their ends. Those chains, known also as magnetic filaments, are created by joining sequentially, one after the other like if a pearl necklace was it, particles smaller than one millionth of meter in size that are magnetic. These filaments are known for its huge potential for the development of novel applications related to nanosensors, and nanoactuators. At the University of the Balearic Islands we have gone a step further by studying such magnetic systems for separation technology as a first step in the development of a novel kind of chromatographic columns. The research has involved computational simulations using special techniques to study in detail the fluid-structure interaction at such microscopic levels. In this work IAC3 researchers have sought first to determine whether it was possible under such strong confinements to control the inner structure properties of the brushes by applying and external magnetic field, and secondly, to determine if it is possible to separate a size-bidisperse mixture of particles using such kind of magnetic setups. Results have shown that it is possible to achieve both aims and that the application of an external magnetic field under such strong confinement conditions leads to non-trivial effects in thebrush structure that can be used to separate a size-bidisperse mixture of particles in two different ways: (a) via a lateral separation (size segregation) of the particles, and (b) via the creation of a difference in the relative mean velocity of the two types of particles. These results are very promising because they pave the way towards the creation of chromatographic columns whose inner properties could be reconfigured via external action, opening the path towards a revolutionary new field in separation technology in which the University of the Balearic Islands is called to play a leading role. The work has been founded by the the Spanish Ministry of Economy and Competitiveness (MINECO/AEI/FEDER,UE) through the project Proyecto de I + D excelencia DPI2017-86610-P.