Optimization of Shapes and Sizes of Moth-Eye-Inspired Structures for the Enhancement of Their Antireflective Properties

Leafhopper-inspired reversibly switchable antireflection coating with sugar apple-like structure arrays

Optical coatings with reversibly tunable antireflective characteristics hold a tremendous potential for next generation optical energy-related applications. Bioinpsired by the camouflage behavior of small yellow leafhoppers, silica hollow sphere/shape memory polymer composites are self-assembled using a non-lithography-based approach. The average visible transmittance of the as-patterned hierarchical structure array-covered substrate is increased by ca. 6.3% at normal incident, and even improved by more than 20% for an incident angle of 75°. Interestingly, the broadband omnidirectional antireflection performance can be reversibly erased and recovered by applying external stimuli under ambient conditions. To gain a better understanding, its reversibility, mechanical robustness, and the structure-shape effect on the antireflective properties are systematically investigated in this research.

Bio-Inspired Nanomaterials for Micro/Nanodevices: A New Era in Biomedical Applications

Exploring bio-inspired nanomaterials (BINMs) and incorporating them into micro/nanodevices represent a significant development in biomedical applications. Nanomaterials, engineered to imitate biological structures and processes, exhibit distinctive attributes such as exceptional biocompatibility, multifunctionality, and unparalleled versatility. The utilization of BINMs demonstrates significant potential in diverse domains of biomedical micro/nanodevices, encompassing biosensors, targeted drug delivery systems, and advanced tissue engineering constructs. This article thoroughly examines the development and distinctive attributes of various BINMs, including those originating from proteins, DNA, and biomimetic polymers. Significant attention is directed toward incorporating these entities into micro/nanodevices and the subsequent biomedical ramifications that arise. This review explores biomimicry's structure-function correlations. Synthesis mosaics include bioprocesses, biomolecules, and natural structures. These nanomaterials' interfaces use biomimetic functionalization and geometric adaptations, transforming drug delivery, nanobiosensing, bio-inspired organ-on-chip systems, cancer-on-chip models, wound healing dressing mats, and antimicrobial surfaces. It provides an in-depth analysis of the existing challenges and proposes prospective strategies to improve the efficiency, performance, and reliability of these devices. Furthermore, this study offers a forward-thinking viewpoint highlighting potential avenues for future exploration and advancement. The objective is to effectively utilize and maximize the application of BINMs in the progression of biomedical micro/nanodevices, thereby propelling this rapidly developing field toward its promising future.

Tunable fabrication of biomimetic polypropylene nanopillars with robust superhydrophobicity and antireflectivity

The fine nanopillars on the natural cicada wing, which exhibits outstanding superhydrophobicity and anti-reflectivity, are carefully observed and analyzed. Here, a promising strategy by combining anodic aluminum oxide template and hot embossing is proposed for rapidly and efficiently mimicking the orderly and densely arranged nanopillars on the cicada wing surface to polypropylene (PP) surfaces. By adjusting the compression pressure, the nanostructures on the PP replica surface gradually evolve from nanoprotrusion-like features to nanopillar-like features so that a gradient wetting behavior from hydrophilicity to hydrophobicity and further to superhydrophobicity appears on the PP replica surfaces. Specifically, the biomimetic PP replica surface exhibits a contact angle of 159 ± 3° and a rolling angle of 8 ± 3° at a compression pressure of 15 MPa. Moreover, the biomimetic PP replica surface can stabilize its superhydrophobic state under a 1.96 kPa external pressure during the dynamic droplet impact. Besides robust dynamic superhydrophobicity, the biomimetic PP replica surface also demonstrated excellent anti-reflectivity because of the gradually changed effective refractive index. Therefore, the biomimetic PP replica inherits both the superhydrophobicity and anti-reflectivity of the natural cicada wing, which makes the products can effectively reduce the external damage when applied to agricultural films, dustproof films, and packaging materials.

Photonic-Plasmonic Nanostructures for Solar Energy Utilization and Emerging Biosensors

Issues related to global energy and environment as well as health crisis are currently some of the greatest challenges faced by humanity, which compel us to develop new pollution-free and sustainable energy sources, as well as next-generation biodiagnostic solutions. Optical functional nanostructures that manipulate and confine light on a nanometer scale have recently emerged as leading candidates for a wide range of applications in solar energy conversion and biosensing. In this review, recent research progress in the development of photonic and plasmonic nanostructures for various applications in solar energy conversion, such as photovoltaics, photothermal conversion, and photocatalysis, is highlighted. Furthermore, the combination of photonic and plasmonic nanostructures for developing high-efficiency solar energy conversion systems is explored and discussed. We also discuss recent applications of photonic-plasmonic-based biosensors in the rapid management of infectious diseases at point-of-care as well as terahertz biosensing and imaging for improving global health. Finally, we discuss the current challenges and future prospects associated with the existing solar energy conversion and biosensing systems.