Curving nanostructures using extrinsic stress

(Figure Presented) We demonstrate the concept of inducing stresses in thin films post-deposition (extrinsic stress) to curve nanostructures on demand. The remarkably high extrinsic stress, induced by triggering grain coalescence in Sn thin films, was used to selfassemble 3D nanostructures with radii of curvature as small as 20 nm. The fabrication methodology required only simple processing steps and the self-assembly process was highly parallel. Curved nanostructures with any desired pattern and both homogeneous (rings, tubes) and variable radii of curvature (spirals, talons) could be constructed.