Large-Area Emerging Patterns by Thermally Engineered Template-Guided Self-Assembly

Template-directed self-assembly is a promising way of manipulating microstructure, enabling emergent functional properties including photonic, phononic, and mechanical. Moreover, the template can evolute microstructures that are distinct from initial starting structures, yielding ordered emerging patterns. However, instabilities at the interfaces between materials and templates hinder the formation of uniformly ordered emerging patterns in a long-range order, limiting practical applications. Here, we design low-thermal fluctuated templates which reduce instability of eutectic self-assembly materials at the interface, leading to a large area (~ 0.01 mm2), ordered checkerboard array of emerging patterns. The FDTD simulation suggests that the low thermal conductivity of the template can minimize temperature fluctuation, giving rise to uniformly ordered emerging patterns. In the serial sectioning of directionally self-assembled AgCl-KCl within the template, we note that microstructures are strongly influenced by the thermal conductivity of the template, and particularly large instability of microstructure at the interface between the template and material results in short-range order. The low thermal conductive template fabricated by porosification constrains thermal fluctuation caused by rapid thermal transport and produces a large-area emerging pattern. We also find that by using selective etching of self-assembled materials or templates, a variety of mesostructures are observed and can control optical properties, which reveal the promising potential for photonic and microscale-based applications.