Friction induces anisotropic propulsion in sliding magnetic microtriangles

Shape anisotropy is important in many microscale systems, being responsible of complex dynamics, interactions and emerging, non-trivial collective behavior. In this talk, I will show that lithographically shaped magnetic microtriangles undergo a series of complex transport modes when driven by a conical precessing magnetic eld. In one of these modes, we find that localized and fast rotations of the triangle tips induce a global surfing-like drift close to the bottom plane. In this sliding regime we exploit the triangle asymmetric shape to obtain a transversal drift which is later used to transport the microtriangle in any direction along the plane. We explain this friction induced anisotropic sliding with a minimal numerical model capable to reproduce the experimental results without considering the complex effect that the triangular shape has on magnetism and hydrodynamics. The flexibility offered by soft lithographic sculpturing, allow to extend this method to guide anisotropic shape magnetic microcomposites to fabricate many other field responsive structures that operate in fluid media.