RogerRoast writes "In a study published in Physical Review B (abstract; full version is paywalled), researchers demonstrate for the first time an approach that allows ferrofluids to be pumped by magnetic fields alone. The invention could lead to new applications for this mysterious material. Though numerous industrial, commercial, and biomedical applications for ferrofluids have since been created, the original goal — to pump liquids with no machinery — remained elusive, until now. The ferrohydrodynamic pump method works when electrodes wound around a pipe force magnetic nanoparticles within the ferrofluids to rotate at varying speeds. Those particles closest to the electrodes spin faster, and it is this spatial variation in rotation speed that propels the ferrofluid forward."