| Confining a (near) critical binary liquid mixtures between structured walls, lateral critical Casimir forces acting on these walls occur. For a colloid opposite to a structured substrate and immersed in a critical solvent, a similar effect arises, and a laterally confining potential emerges. Experimental data for such potentials, the strength of which is tunable by temperature, are compared with theoretical predictions. A colloid opposite to a chemically patterned substrates may even levitate at a stable distance above the substrate due to the critical Casimir effect. Non-spherical colloids close to homogeneous substrate experience a critical Casimir torque upon approaching the critical point of the solvent. |
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