Highly ordered nanopatterns are obtained at sub‐5 nm periodicities by the graphoepitaxial directed self‐assembly of monodisperse, oligo(dimethylsiloxane) liquid crystals. These hybrid organic/inorganic liquid crystals are of high interest for nanopatterning applications due to the combination of their ultrasmall feature sizes and their ability to be directed into highly ordered domains without additional annealing.

The thin‐film directed self‐assembly of molecular building blocks into oriented nanostructure arrays enables next‐generation lithography at the sub‐5 nm scale. Currently, the fabrication of inorganic arrays from molecular building blocks is restricted by the limited long‐range order and orientation of the materials, as well as suitable methodologies for creating lithographic templates at sub‐5 nm dimensions. In recent years, higher‐order liquid crystals have emerged as functional thin films for organic electronics, nanoporous membranes, and templated synthesis, which provide opportunities for their use as lithographic templates. By choosing examples from these fields, recent progress toward the design of molecular building blocks is highlighted, with an emphasis on liquid crystals, to access sub‐5 nm features, their directed self‐assembly into oriented thin films, and, importantly, the fabrication of inorganic arrays. Finally, future challenges regarding sub‐5 nm patterning with liquid crystals are discussed.

In this work, light and temperature responsive, brush‐painted photonic coatings exhibiting three different colored and surface topographical states are reported. The different states arise from the use of cholesteric liquid‐crystalline micrometer‐sized polymer particles as shape‐memory photonic pigments that are dispersed in a shape‐memory binder. The first temporal state is induced by compressing the photonic particles at high temperature, resulting in blueshift of the structural color. The second temporal state is obtained by embossing a diffractive grating on the surface at an intermediate temperature leading to a relief topography and a rainbow optical effect. Both optical and surface topographical changes coexist and are stable at room temperature until they are reverted independently either by heating or locally by light illumination. Multicolored paints that reflect selectively left‐handed or right‐handed polarized light are developed to create arbitrary polarization‐dependent multicolor and topographical brush‐painted patterns. These temperature and light responsive triple shape‐memory photonic paints have potential applications as battery‐free optical sensors, responsive decoration, and smart adhesives.

Highly transparent, ultradrawn high-density polyethylene (HDPE) films were successfully prepared using compression molding and solid-state drawing techniques. The low optical transmittance (<50%) of the pure drawn HDPE films can be drastically improved (>90%) by incorporating a small amount (>1 wt %/wt) of specific additives to HDPE materials prior to drawing. It is shown that additives with relatively high refractive index result in an increased optical transmittance in the visible light wavelength which illustrates that the improvement in optical characteristics probably originates from refractive index matching between the crystalline and noncrystalline regions in the drawn films. Moreover, the optically transparent drawn HDPE films containing additives maintain their physical and mechanical properties, especially their high modulus and high strength, which make these films potentially useful in a variety of applications, such as high-impact windows.

optical time-analyte indicators. [21,22] Regular surface topographies exhibiting structural colors have been fabricated in SMPs by top-down methods including locally induced surface wrinkling, [23] nanoimprint lithography, [24,25] compression molding, [26] or templating via microspheres. [27] In these examples, hot pressing of the surface features results in a temporary flattened and colorless state, which is reversible upon heating. [24][25][26][27] To circumvent the cumbersome topdown nanoforming steps to generate the structural color, photonic SMP coatings generated by bottom-up self-assembly have also been employed. [17,28,29] For example, shape memory photonic films have been produced from core-interlayer-shell polymer microspheres that form opal structures. [30][31][32] Alternatively porous inverse-opal SMPs have been templated by silica colloids. [33] Capillary pressure-induced "cold" programming of these materials results in a disordered temporary state consisting of collapsed pores and an arbitrarily roughened surface, which can be recovered by pressure, heat, organic vapors, solvents, and microwave radiation. [34][35][36][37][38][39] Unfortunately, the fabrication of such SMP coatings is still hampered by the lack of facile methods and materials. [40] Reactive liquid crystalline materials are exciting from this perspective since they form nanostructured phases via selfassembly, and can be easily processed via photopolymerization [41][42][43][44] to fabricate polymeric coatings. [45][46][47][48][49] Chiral nematic liquid crystalline (a.k.a. cholesteric liquid crystalline (CLC)) phases are of particular interest for their periodic helical structures which lead to the selective and incident-angledependent reflection of light, resulting in iridescent structural colors. [50] CLC coatings have been reported that respond to stimuli including heat, light, and humidity. [17,[51][52][53][54][55][56][57] In addition, CLC coatings have been reported that simultaneously change surface topography and color in a reversible manner. [41,55] Recently, our group reported that irreversible thermoresponsive photonic coatings can be fabricated based on CLC polymer networks using a shape memory approach. [58,59] Indentation of a small area (≈1 mm 2 ) of the CLC film, at a temperature above the T g of the polymer network, resulted in a blue-shift of the reflection band through a reduction of the pitch of the cholesteric helix, which was fully recovered upon heating.We now report a new approach for the fabrication of shape memory photonic coatings that irreversibly change both topography and color. Polymeric CLC films with a red structural The fabrication of shape memory coatings that change both reflectivity and topography is hampered by the lack of facile methods and materials. Now, shape memory photonic coatings are fabricated by high-speed flexographic printing and UV-curing in air of a chiral nematic liquid crystal ink. Deformable polymeric films with a red reflection band and a smooth surface topography are obtained which...