“These larger crystals are easier to control using external magnetic fields, and they will not aggregate when those fields are removed, which will make them much more useful in practical applications, including drug delivery,” Kezheng Chen from Quingdou University of Science and Technology in Quingdou, China. In theory, superparamagnetic particles could be ideal for drug delivery as they can be directed to a tumor simply by using an external magnetic field. And this is just the beginning. Chen’s might, for example, crystals be useful in the many engineering projects that need “smart fluids” that change their properties when a magnetic field is applied. Now that superparamagnetism is no longer restricted to minute particles that are difficult to handle, researchers can start exploring in which ways this can contribute to improving our lives. This method of making larger superparamagnetic crystals paves the way for the development of superparamagnetic bulk materials that can be reliably controlled by moderate external magnetic forces.