Long-wave infrared (LWIR) imaging, or thermal imaging, is widely applied in night vision and security monitoring. However, the widespread use of LWIR imagers is impeded by their bulky size, considerable weight, and high cost. While flat meta-optics present a potential solution to these limitations, existing pure LWIR meta-optics face constraints such as severe chromatic or coma aberrations. Here, we introduce an approach utilizing large-scale hybrid meta-optics to address these challenges and demonstrate the achromatic, coma-corrected, and polarization-insensitive thermal imaging. The hybrid metalens doublet is composed of a metasurface corrector and a refractive lens, featuring a full field-of-view angle surpassing 20° within the 8-12 μm wavelength range. Employing this hybrid metalens doublet, we showcase high-performance thermal imaging capabilities both indoors and outdoors, effectively capturing ambient thermal radiation. The proposed hybrid metalens doublet holds considerable promise for advancing miniaturized, lightweight, and cost-effective LWIR optical imaging systems.
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http://dx.doi.org/10.1021/acs.nanolett.4c01218 | DOI Listing |
Sensors (Basel)
December 2024
Department of Electrical and Computer Engineering, University of Missouri, Columbia, MO 65211, USA.
Multi-modal systems extract information about the environment using specialized sensors that are optimized based on the wavelength of the phenomenology and material interactions. To maximize the entropy, complementary systems operating in regions of non-overlapping wavelengths are optimal. VIS-IR (Visible-Infrared) systems have been at the forefront of multi-modal fusion research and are used extensively to represent information in all-day all-weather applications.
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December 2024
Department of Mechanical & Aerospace Engineering, Monash University, Clayton, VIC 3800, Australia.
This study presents a novel approach for monitoring waste substrate digestion under high-density polyethylene (HDPE) geomembranes in sewage treatment plants. The method integrates infrared thermal imaging with a clustering algorithm to predict the distribution of various substrates beneath Traditional outdoor large-scale opaque geomembranes, using solar radiation as an excitation source. The technique leverages ambient weather conditions to assess the thermal responses of HDPE covers.
View Article and Find Full Text PDFPolymers (Basel)
December 2024
Institute of Chemistry, Federal University of Rio Grande do Sul (UFRGS), Bento Gonçalves 9500, Porto Alegre 90010-150, RS, Brazil.
This study reported a one-spot preparation of magnetic composite carbon (MCC@Fe) from microcrystalline cellulose (MC). The pure cellulose was impregnated in iron (III) chloride solution and carbonized at 650 °C. The MCC@Fe composite adsorbent underwent various characterization techniques.
View Article and Find Full Text PDFMaterials (Basel)
December 2024
Department of Mechanics of Materials and Constructions, Faculty of Engineering, Vrije Universiteit Brussel, B-1050 Brussels, Belgium.
Cementitious materials are susceptible to damage not only from mechanical loading, but also from environmental (physical, chemical, and biological) factors. For Textile-Reinforced Cementitious (TRC) composites, durability poses a significant challenge, and a reliable method to assess long-term performance is still lacking. Among various durability attacks, freeze-thaw can induce internal cracking within the cementitious matrix, and weaken the textile-matrix bond.
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December 2024
Centre of Materials and Building Technologies (C-MADE), Department of Civil Engineering and Architecture, University of Beira Interior (UBI), 6201-001 Covilhã, Portugal.
The paper examines the impact of passive restraint on fire-induced spalling in concrete, utilizing a concrete mixture to minimize compositional variability. A variety of specimen geometries was prepared, including standard cubes and cylinders for the determination of mechanical properties and slabs of different dimensions for fire spalling tests conducted under controlled conditions. A top-opening Dragon furnace, which applies ISO 834-1 fire curves, was used to evaluate the influence of "cold rim" boundaries, where slab edges were insulated to create thermal restraint.
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