Self-assembled periodic liquid crystal defects array for soft lithographic template

Abstract

We have developed highly periodic patterns with sub-micrometer features over large-areas using toric focal conic domains (TFCDs) originated from smectic liquid crystal (LC) as a new self-assembling building block. TFCDs are accomplished by precisely controlling the surface and interfacial properties of smectic LC. In order to apply the smectic liquid crystal defect arrays in soft lithography, the hexagonal arrays of domain patterns are used as molds for ultraviolet (UV) curable polymers, thereby providing LC defect stamps with high spatial resolution over large areas. Our method was further utilized to transfer patterns with sub-micrometer features from the polymer stamp surface to a secondary surface by microcontact printing (mu-CP). Accordingly, we show that such LC materials can be very strong candidates for the periodic templates, compared to other soft-building blocks such as block copolymers, colloids and surfactants. We anticipate our finding be a starting point for more sophisticated lithographic applications based on liquid crystalline materials.