Sculpting asymmetric, hollow-core, three-dimensional nanostructures using colloidal particles.

Colloidal elements have historically played a key role in "bottom-up" self-assembly processes for nanofabrication. However, these elementary components can also interact with light to generate complex intensity distributions and facilitate "top-down" lithography. Here, a nanolithography technique is demonstrated based on oblique illuminations of colloidal particles to fabricate hollow-core 3D nanostructures with complex symmetry. The light-particle interaction generates an angular light distribution as governed by Mie scattering, which can be compounded by multiple illuminations to sculpt novel 3D structures in the underlying photoresist. The fabricated geometry can be controlled by the particle parameters and illumination configurations, enabling the fabrication of a large variety of asymmetric hollow nanostructures. The proposed technique has high pattern versatility, is low cost and high throughput, and can find potential application in nanoneedles, nanonozzles, and materials with anisotropic properties.