Wall-induced translation of a rotating particle in a shear-thinning fluid

Particle–wall interactions have broad biological and technological applications. In particular, some artificial microswimmers capitalize on their translation–rotation coupling near a wall to generate directed propulsion. Emerging biomedical applications of these in complex fluids prompt questions the impact non-Newtonian rheology this work, we report intriguing effects shear-thinning rheology, ubiquitous behaviour fluids, particle wall. One particularly interesting feature revealed here is that wall-induced translation by rotation can occur direction opposite what might be intuitively expected for an object rolling solid substrate. We elucidate underlying physical mechanism discuss its implications design micromachines bacterial motion walls fluids.