(383i) Tuning the Orientation of Small Microorganisms with Magnetic Fields

The development of the next generation of microbots faces significant challenges due to the miniaturization and integration of complex functionalities. However, living colloids, ranging from single-celled to multicellular organisms, offer a promising solution as ultra-functional active matter that operates autonomously at small length-scales. To this end, we propose using magnetically responsive nanoparticle (NP) dispersions to manipulate non-magnetic microorganisms through negative magnetostatics. Our investigation focuses on using this approach to control the motion and spatial distribution of non-magnetic wild-type Caenorhabditis elegans, suspended in a biocompatible NP dispersion and exposed to external magnetic fields. Our results demonstrate that magnetic fields are a versatile and generalizable tool for controlling living organisms, with the limitation being the competition between external applied force and the internal forces of the organism itself.