Enabling nanotechnology with self assembled block copolymer patterns

TLDR

Block copolymers have attracted attention for decades, and in the past decade their tunable microdomains have positioned them as promising materials for nanotechnology, where control over domain size, shape, periodicity, and orientation is essential for exploiting their transport, mechanical, electrical, and optical properties. The review surveys current nanotechnological applications of BCPs—such as membranes, nanoparticle templates, photonic crystals, and high‑density storage—and examines methods for controlling their microdomain structures in bulk and thin films. Microdomain structures are manipulated through external biases—mechanical flow, electric fields, temperature gradients, and surface interactions—with particular emphasis on epitaxy and graphoepitaxy techniques and their combinations. Employing multiple external fields to manipulate BCP microdomains holds promise for realizing diverse nanotechnological applications.

Abstract

Block copolymers (BCPs) have received great attention for the past 40 years but only within the past decade have they been seriously considered for nanotechnological applications. Their applicability to nanotechnology stems from the scale of the microdomains and the convenient tunability of size, shape, and periodicity afforded by changing their molecular parameters. The use of the tensorial physical properties of BCPs in such areas as transport, mechanical, electrical, and optical properties will provide substantial benefits in the future. In this review article, we first focus on the current efforts to utilize BCPs in nanotechnologies including nanostructured membranes, BCP templates for nanoparticle synthesis, photonic crystals, and high-density information storage media. In order to realize these applications, control over microdomain spatial and orientational order is paramount. This article reviews various methods to control BCP microdomain structures in the bulk state as well as in thin films. A variety of biases such as mechanical flow fields, electric fields, temperature gradients, and surface interactions can manipulate the microstructures of BCPs. A particular emphasis is made on two approaches, epitaxy and graphoepitaxy, and their combinations. Manipulation of BCP microdomain structures employing multiple external fields promises realization of many potential nanotechnological applications.