Morphology-Driven Magnetic Property Manipulation in Binary Particle Mixtures for Microscale Magnetic Control.

Magnetic microactuators and microrobots have the potential to revolutionize remote manipulation and swarm-based collaboration. Unfortunately, conventional approaches to controlling individual magnetic systems cannot be shrunk to the microscale due to fundamental challenges in the generation and modification of magnetic fields. We here demonstrate the manipulation of magnetic properties in binary particle mixtures through morphology control. A combination of ferromagnetic and non-magnetic particles demonstrates the emergence of ordering and magnetic anisotropy under conditions that induce mechanical jamming in the assembly. A combined theoretical and experimental investigation confirms the importance of arresting forces from neighboring particles as the origin of this behavior. Utilizing this insight, a novel actuator, termed “Magnet with Mechanical Tunability (MagMeT)” was developed that transduces mechanical deformation in magneto/elastomer particle mixtures into magnetic torque. Our results open up a route toward actively controlling magnetic microrobots for future remote operating applications.