Self-Directed Self-Assembly of 3D Tailored Block Copolymer Nanostructures

Area of Science:

• Materials Science
• Nanotechnology
• Polymer Science

Background:

• Directed self-assembly (DSA) of block copolymers (BCPs) is effective for 2D nanostructures.
• Fabricating uniform and complex 3D nanostructures via BCP self-assembly remains a significant challenge.

Purpose of the Study:

• To introduce and validate a novel method for fabricating complex 3D nanostructures using BCPs.
• To demonstrate the capability of self-directed self-assembly (SDSA) for creating multilayered nanostructures.

Main Methods:

• Utilized dissipative particle dynamics (DPD) simulations to model the self-assembly process.
• Employed alternating stacking of orthogonal AB and AC copolymer films.
• Investigated the propagation of structural information from the substrate upwards through layers.

Main Results:

• Achieved uniform multilayer nanostructures by alternating orthogonal BCP films (AB and AC).
• Demonstrated self-directed self-assembly (SDSA) where each new layer self-assembles on the previous one.
• Showcased the fabrication of diverse 3D nanostructures, including aligned cylinders, spheres on cylinders, and orthogonal nanomeshes, by varying layer compositions.

Conclusions:

• The proposed SDSA method enables the creation of tailored, complex 3D nanostructures from BCPs without cross-linking or etching.
• This approach allows for the combination of different bulk phases within layers, expanding possibilities beyond single-phase 3D systems.
• Integration with grapho- or chemo-epitaxy allows surface patterns to evolve into intricate 3D nanostructures.