Filtering specific molecules is a challenge faced for several vital needs: from biomedical applications like dialysis to the intensive production of clean water. The domain has been boosted over the last decades by the possibilities offered by nanoscale materials. Filtration is however always designed according to a passive sieving perspective: a membrane with small and properly decorated pores allows for the selection of the targeted molecules. This inevitably impedes the flux and transport, making separation processes costly in terms of energy. Here we investigate alternative approaches to separation and filtration. We explore the possibility of non-equilibrium sieving, harnessing the difference in the molecular dynamics of particles to separate them across “active” nanopores.