Friction Induces Anisotropic Propulsion in Sliding Magnetic Microtriangles

Junot, Gaspard; Leyva, Sergi G.; Pauer, Christoph; Calero, Carles; Pagonabarraga, Ignacio; Liedl, Tim; Tavacoli, Joe und Tierno, Pietro (2022): Friction Induces Anisotropic Propulsion in Sliding Magnetic Microtriangles. In: Nano Letters, Bd. 22, Nr. 18: S. 7408-7414

Abstract

In viscous fluids, motile microentities such as bacteria or artificial swimmers often display different transport modes than macroscopic ones. A current challenge in the field aims at using friction asymmetry to steer the motion of microscopic particles. Here we show that lithographically shaped magnetic microtriangles undergo a series of complex transport modes when driven by a precessing magnetic field, including a surfing-like drift close to the bottom plane. In this 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. Due to the flexibility offered by soft-lithographic sculpturing, our method to guide anisotropic-shaped magnetic microcomposites can be potentially extended to many other field responsive structures operating in fluid media.

• Dokumententyp: Zeitschriftenartikel
• Fakultät: Physik
• Themengebiete: 500 Naturwissenschaften und Mathematik > 530 Physik
• ISSN: 1530-6984
• Sprache: Englisch