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In optics, the refractive index of a material and its spatial distribution determine the characteristics of light propagation. Therefore, exploring both low- and high-index materials/structures is an important consideration in this regard. Hollow cavities, which are defined as low-index bases, exhibit a variety of unusual or even unexplored optical characteristics and are used in numerous functionalities including diffraction gratings, localised optical antennas and low-loss resonators. In this report, we discuss the fabrication of hollow cavities of various sizes (0.2-5 μm in diameter) that are supported by conformal dielectric/metal shells, as well as their specific applications in the ultraviolet (photodetectors), visible (light-emitting diodes, solar cells and metalenses), near-infrared (thermophotovoltaics) and mid-infrared (radiative coolers) regions. Our findings demonstrate that hollow cavities tailored to specific spectra and applications can serve as versatile optical platforms to address the limitations of current optoelectronic devices. Furthermore, hollow cavity embedded structures are highly elastic and can minimise the thermal stress caused by high temperatures. As such, future applications will likely include high-temperature devices such as thermophotovoltaics and concentrator photovoltaics.
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http://dx.doi.org/10.1038/s41377-022-01021-1 | DOI Listing |
Colloids Surf B Biointerfaces
August 2025
School of Stomatology, Qingdao University, Qingdao 266023, PR China; Department of Orthodontics, The Affiliated Hospital of Qingdao University, Qingdao 266003, PR China.
White spot lesions (WSLs) are the most common complication of orthodontic treatment, compromising dental health and significantly affecting aesthetics. To address this clinical challenge, this study aims to develop a dual-functional therapeutic strategy that simultaneously promotes the remineralization of demineralized enamel and inhibits the activity of cariogenic bacteria, thereby achieving effective prevention and treatment of WSLs. A hollow double-shell structured CuO@N/C nanozyme (H-CuO@N/C) was synthesized using a one-step hydrothermal method.
View Article and Find Full Text PDFChem Asian J
August 2025
State Key Laboratory of Tropic Ocean Engineering Materials and Materials Evaluation, Hainan University, Haikou, 570228, China.
Submicron catalysts with tailored 3D architectures offer unique opportunities to manipulate nanoscale mass transport and active site distribution, thereby enhancing catalytic performance. Herein, we constructed a yolk-shell FeO@H-ZrO carrier to provide a semi-open interstitial cavity. Subsequently, Pd nanoparticles were introduced into this cavity by a vacuum-assisted strategy, which resulted in precise confinement and uniform dispersion of Pd nanoparticles.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
August 2025
State Key Laboratory of Silicate Materials for Architecture & School of Chemistry, Chemical Engineering and Life Science & State Key Laboratory of Advanced Technology for Materials Synthesis and Processing & School of Materials Science and Engineering, Wuhan University of Technology, Wuhan, 430070,
Biological membrane-enclosed organelles, in which cascade reactions promoted by multiple enzymes occur, have inspired widespread interest in the design of spatially confined nanoreactors for tandem catalytic transformations. Because of their accessible compartmentalized environments and large framework diversity, hollow metal-organic frameworks (H-MOFs) are ideal platforms for the development of new multi-functionalized nanoreactors. However, simple methodologies for fabrication of hollow MOFs, which possess functionalities that are precisely localized and encapsulated of active sites like those found in biological membrane-enclosed organelles, is a considerable challenge.
View Article and Find Full Text PDFInt J Biol Macromol
September 2025
National Engineering Laboratory for Modern Silk, College of Textile and Clothing Engineering, Soochow University, Suzhou 215123, China. Electronic address:
Liraglutide demonstrates a glucose-dependent hypoglycemic mechanism with significant therapeutic potential for type 2 diabetes mellitus. This study developed a hollow microneedle system featuring dual drug loading mechanisms cavity encapsulated and matrix embedded to achieve sustained release of liraglutide. The cavity structure avoids direct contact between the drug and the silk fibroin shell, as well as the binding state transition caused by hydrophobic interactions.
View Article and Find Full Text PDFPrecise monitoring of the microfluidic flow rate is a key factor in microfluidic chips. However, the temperature of the microfluidics often affects the measuring results of the optical flow rate sensor. Here, we present a fiber-tip optical sensor based on a three-beam interferometer that can measure microfluidic flow rate and temperature simultaneously.
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