Normal and shear forces generated during the ordering (directed assembly) of confined straight and curved nanowires.

The effects of shape on nanowire interactions and shear-induced ordering were studied. Both the normal and lateral forces were sensitive to the particles' curvature. (i) No adhesion was observed between the confining surfaces, and the force profiles were short-ranged and mostly reversible for straight wires but longer-ranged and irreversible for curved wires. (ii) Structural phase transitions can occur in confined nanoparticle films. (iii) During shearing, straight wires order or align more easily than curved wires.