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Medical plastic-appliance-based healthcare services, especially in dentistry, generate tremendous amounts of plastic waste. Given the physiological features of our mouth, it is desirable to substitute dental care plastics with viscoelastic and antimicrobial bioplastics. Herein, we develop a medical-grade and sustainable bioplastic that is viscoelastic enough to align the tooth positions, resists microbial contamination, and exhibits recyclable life cycles. In particular, we devise a molecular template involving entanglement-inducing and antimicrobial groups and prepare a silk fibroin-based dental care bioplastic. The generated compactly entangled structure endows great flexibility, toughness, and viscoelasticity. Therefore, a satisfactory orthodontic outcome is accomplished, as demonstrated by the progressive alignment of male rabbit incisors within the 2.5 mm range. Moreover, the prepared bioplastic exhibits resistance to pathogenic colonization of intraoral microbes such as Streptococcaceae and Veillonellaceae. Because the disentanglement of entangled domains enables selective separation and extraction of the components, the bioplastic can be recycled into a mechanically identical one. The proposed medical-grade and sustainable bioplastic could potentially contribute to a green healthcare future. Medical plastic-appliance-based healthcare services, especially in dentistry, generate large amounts of plastic waste. Here, the authors address this issue by developing a medical-grade and sustainable bioplastic that is viscoelastic enough to align the tooth positions, resists microbial contamination, and exhibits recyclable life cycles. [ABSTRACT FROM AUTHOR]

A gyroid crystal possesses a peculiar structural feature that can be conceptualized as a triply periodic surface with a constant mean curvature of zero. The exotic optical properties such as the photonic bandgap and optical chirality can emerge from this three-dimensional (3D) morphological feature. As such, gyroid crystals have been considered as the promising structures for photonic crystals and optical metamaterials. To date, several methods have been proposed to materialize gyroid crystals, including 3D printing, layer-by-layer stacking, two-photon lithography, interference lithography, and self-assembly. Furthermore, the discovery of Weyl points in gyroid crystals has further stimulated these advancements. Among such methods, the self-assembly of block copolymers (BCPs) is unique, because this soft approach can provide an easy-to-craft gyroid, especially at the nanoscale. The unit-cell scale of a gyroid ranging within 30–300 nm can be effectively addressed by BCP self-assembly, whereas other methods would be challenging to achieve this size range. Therefore, a BCP gyroid has provided a material platform for metamaterials and photonic crystals functioning at optical frequencies. Currently, BCP gyroid nanophotonics is ready to take the next step toward topological photonics beyond the conventional photonic crystals and metamaterials. In particular, the intrinsic lattice transformations occurring during the self-assembly of BCP into a gyroid crystal could promise a compelling advantage for advancing Weyl photonics in the optical regime. Lattice transformations are routinely considered as limitations, but in this review, we argue that it is time to widen the scope of the lattice transformations for the future generation of nanophotonics. Thus, our review provides a comprehensive understanding of the gyroid crystal and its lattice transformations, the relevant optical properties, and the recent progress in BCP gyroid self-assembly.

Despite the remarkable progress in the development of sweat sensors, self‐powered sweat‐responsive sensing displays that detect sweat in electric signals with simultaneous and direct visualization of the sweat is rarely demonstrated. Here, a self‐powered sweat‐responsive structural color (SC) display enabled by ionomer‐doped block copolymer (BCP) photonic crystals (PCs) is presented. The sweat‐responsive BCP PC is developed by employing a cross‐linking single‐mobile ionomer (SMI) with mobile anions anchored to immobile polycations to a 1‐D BCP PC. The hydrophobic SMI‐doped BCP PC is mechanically robust as well as water and temperature‐resistive, exhibiting ionomer concentration‐dependent full visible SCs. Moreover, the mobile anions periodically confined in the SMI‐doped BCP PC harvest triboelectric energy, giving rise to a high‐power density of ≈0.774 Mw cm−2. Cation‐sensitive SC variation is observed in the SMI‐doped BCP PC, allowing the visualization of sweat containing various cations. A skin‐patchable self‐powered sweat‐responsive display is demonstrated in which kirigami‐patterned SMI‐doped BCP PC incorporated in the display can withstand up to 50% strain during exercise. Sweat from the exercise is visualized via SC display and measured using both ionic resistance changes and triboelectric signals. In addition, the integration of sweat sensing membrane into SMI‐doped BCP PC enables the quantification of sweat. [ABSTRACT FROM AUTHOR]

Photovoltaic (PV) technology enables the conversion of solar energy into electricity. Si-based PV modules, which currently represent more than 90% of the global PV market, are expected to be in high demand in the future. To increase the efficiency of Si-based PV modules, it is important to improve not only the manufacturing technology and solar cell architecture but also the materials needed to produce the modules. Encapsulants and backsheets, which are used to ensure the long-term lifespan and stability of solar cells, play an equally important role in PV modules as solar cells. Research is being conducted on polymers used in encapsulants and backsheets to increase cell efficiency by using additives or composites with various materials. This article reviews the recent developments of materials and additives for polymer-based encapsulants and backsheets in Si-based PV modules. [ABSTRACT FROM AUTHOR]

A perspective is presented on recent developments in block copolymers (BCPs), capable of forming sub‐10 nm nanostructures and bottlebrush block copolymers (BBCPs), capable of forming supra‐100 nm nanostructures. Over the last few decades, BCP research has emphasized pattern miniaturization for application in next‐generation lithography tools in the semiconductor industry. The first part focuses on the recent efforts that investigated high‐χ linear BCPs evolved from conventional poly(styrene‐b‐methyl methacrylate) (PS‐b‐PMMA) pairs. Recently, novel BCP structures capable of forming nanostructures with significant periodicities for controlling visible light have gained considerable attention. The second part reviews the literature on BBCPs that exhibit the potential to create supra‐100 nm nanostructures. Finally, the future aspect on BCP lithography is discussed. [ABSTRACT FROM AUTHOR]