Systems, methods and devices are presented for extracting target particles within a ferrofluid medium. In some embodiments, a fluidic channel receives a flow of a mix of one or more types of target particles, where at least one magnetic field source is configured to react with the flow such that a force (indirect or direct) is placed on the particles of the mix, across the width and/or the height of the fluidic channel. An extraction opening placed on one wall is provided and configured to extract at least one type of target particle.