scholarly journals Transfer Tiling of Nanostructures for Large-Area Fabrication

Micromachines ◽  
2018 ◽  
Vol 9 (11) ◽  
pp. 569
Author(s):  
Jaekyoung Kim ◽  
Hyunsik Yoon
Keyword(s):  
Exposure Time ◽  
Optical Component ◽  
Uv Exposure ◽  
Process Window ◽  
Shadow Mask ◽  
Large Area ◽  
Naked Eye ◽  
Nanoscale Patterns ◽  
Optical Applications ◽  
Overlapped Region

The fabrication of nanoscale patterns over a large area has been considered important but difficult, because there are few ways to satisfy both conditions. Previously, visually tolerable tiling (VTT) for fabricating nanopatterns for optical applications has been reported as a candidate for large area fabrication. The essence of VTT is the inevitable stitching of the nanoscale optical component, which is not seen by the naked eye if the boundary is very narrow while the tiles are overlapped. However, it had been difficult to control the shape of the spread of liquid prepolymers in the previous work, and there was room for the development of tiling. Here, we propose a method for transferring various shapes of tiles, which can be defined with a shadow mask. The method of using a transparent shadow mask can provide a wide process window, because it allows the spreading of a liquid prepolymer to be more easily controlled. We optimize the coating condition of a liquid prepolymer and the ultraviolet (UV) exposure time. Using this method, we can attach tiles of various shapes without a significant visible trace in the overlapped region.

Large-Area Metal Gaps and Their Optical Applications

2018 ◽  
Vol 7 (1) ◽  
pp. 1800426 ◽  
Author(s):  
Young-Mi Bahk ◽  
Dai-Sik Kim ◽  
Hyeong-Ryeol Park
Keyword(s):  
Large Area ◽  
Optical Applications

scholarly journals Hyperchromatic structural color for perceptually enhanced sensing by the naked eye

2020 ◽  
Vol 117 (48) ◽  
pp. 30107-30117
Author(s):  
Tahmid H. Talukdar ◽  
Bria McCoy ◽  
Sarah K. Timmins ◽  
Taufiquar Khan ◽  
Judson D. Ryckman
Keyword(s):  
High Performance ◽  
Limit Of Detection ◽  
Form Factors ◽  
Optical Filters ◽  
Color Filter ◽  
Structural Color ◽  
Label Free ◽  
Colorimetric Sensing ◽  
Large Area ◽  
Naked Eye

Colorimetric sensors offer the prospect for on-demand sensing diagnostics in simple and low-cost form factors, enabling rapid spatiotemporal inspection by digital cameras or the naked eye. However, realizing strong dynamic color variations in response to small changes in sample properties has remained a considerable challenge, which is often pursued through the use of highly responsive materials under broadband illumination. In this work, we demonstrate a general colorimetric sensing technique that overcomes the performance limitations of existing chromatic and luminance-based sensing techniques. Our approach combines structural color optical filters as sensing elements alongside a multichromatic laser illuminant. We experimentally demonstrate our approach in the context of label-free biosensing and achieve ultrasensitive and perceptually enhanced chromatic color changes in response to refractive index changes and small molecule surface attachment. Using structurally enabled chromaticity variations, the human eye is able to resolve ∼0.1-nm spectral shifts with low-quality factor (e.g., Q ∼ 15) structural filters. This enables spatially resolved biosensing in large area (approximately centimeters squared) lithography-free sensing films with a naked eye limit of detection of ∼3 pg/mm2, lower than industry standard sensors based on surface plasmon resonance that require spectral or angular interrogation. This work highlights the key roles played by both the choice of illuminant and design of structural color filter, and it offers a promising pathway for colorimetric devices to meet the strong demand for high-performance, rapid, and portable (or point-of-care) diagnostic sensors in applications spanning from biomedicine to environmental/structural monitoring.

scholarly journals Vitamin D Status in Japanese Adults: Relationship of Serum 25-Hydroxyvitamin D with Simultaneously Measured Dietary Vitamin D Intake and Ultraviolet Ray Exposure

Nutrients ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 743 ◽  
Author(s):  
Keiko Asakura ◽  
Norihito Etoh ◽  
Haruhiko Imamura ◽  
Takehiro Michikawa ◽  
Takahiro Nakamura ◽  
...  
Keyword(s):  
Vitamin D ◽  
Exposure Time ◽  
Serum Vitamin ◽  
Vitamin D Insufficiency ◽  
Uv Exposure ◽  
Dietary Vitamin ◽  
Hydroxyvitamin D ◽  
Vitamin D Intake ◽  
25 Hydroxyvitamin D ◽  
Ultraviolet Ray

Vitamin D insufficiency/deficiency is prevalent worldwide. We investigated the effect of vitamin D intake and ultraviolet ray (UV) exposure on serum vitamin D concentration in Japan. A total of 107 healthy adult participants were recruited from Hokkaido (43° N) and Kumamoto (33° N) prefectures. All participants undertook surveys in both summer and winter. Serum 25-hydroxyvitamin D (25(OH)D3) was examined, and vitamin D intake was assessed with a diet history questionnaire. UV exposure was measured with a wearable UV dosimeter. Regression analysis was performed to investigate the relationship between these factors, with covariates such as sun avoidance behavior. The prevalence of vitamin D insufficiency (serum 25(OH)D3; 12 ng/mL (30 nmol/L) ≤ and <20 ng/mL (50 nmol/L))/deficiency (<12 ng/mL) was 47.7% in summer and 82.2% in winter. UV exposure time was short in Kumamoto (the urban area), at 11.6 min in summer and 14.9 min in winter. In Hokkaido (the rural area), UV exposure time was 58.3 min in summer and 22.5 min in winter. Vitamin D intake was significantly associated with serum 25(OH)D3, and a 1 μg/1000kcal increase in intake was necessary to increase 25(OH)D3 by 0.88 ng/mL in summer and by 1.7 ng/mL in winter. UV exposure time was significantly associated with serum 25(OH)D3 in summer, and a 10 min increase in UV exposure time was necessary to increase 25(OH)D3 by 0.47 ng/mL. Although consideration of personal occupation and lifestyle is necessary, most Japanese may need to increase both vitamin D intake and UV exposure.

Effects of Culture Media, Exposure Time and Temperature on Near-Ultraviolet-Induced Sporulation of Alternaria alternata

1985 ◽  
Vol 48 (4) ◽  
pp. 316-319
Author(s):  
CHENG-I WEI ◽  
DIANE D. SWARTZ ◽  
JOHN A. CORNELL
Keyword(s):  
Exposure Time ◽  
Alternaria Alternata ◽  
Culture Medium ◽  
Culture Media ◽  
Media Exposure ◽  
Potato Dextrose Agar ◽  
Uv Exposure ◽  
Strain Atcc ◽  
Ultraviolet Exposure ◽  
Near Ultraviolet

Effects of culture media, near-ultraviolet exposure time, and temperature on sporulation of Alternaria alternata were investigated. Strains RL 671-2 and ATCC 36068 were cultivated on Potato Dextrose Agar (PDA), V8 Juice Agar (V8 Agar) and Mycological Agar (MA). The best culture medium for sporulation of strain RL 671-2 was PDA, followed by V8 agar, with only negligible numbers of spores appearing on MA. Near-UV exposure significantly increased sporulation in strain RL 671-2 on PDA and V8 agar. Significantly higher (P&lt;0.01) spore counts were found in PDA cultures of this strain exposed to near-UV at 35 than at 20°C. On V8 agar significantly more spores were observed at 20 than at 35°C. MA was not a satisfactory medium for sporulation of ATCC 36068. Both PDA and V8 agar equally supported sporulation for this strain (ATCC 36068) at all exposure times.

Large-Area, Low-Cost Infrared Metamaterial Fabrication Via Pulsed Laser Deposition with Metallic Mesh as a Shadow Mask

Plasmonics ◽  
2015 ◽  
Vol 11 (2) ◽  
pp. 373-379 ◽  
Author(s):  
Zidong Zhang ◽  
Shuhui Chen ◽  
Xiujie Ji ◽  
Chen Qin ◽  
Huimin Wang ◽  
...  
Keyword(s):  
Pulsed Laser Deposition ◽  
Low Cost ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
Shadow Mask ◽  
Large Area ◽  
Metallic Mesh

Degradation of PVDF-based composite membrane and its impacts on membrane intrinsic and separation properties

2016 ◽  
Vol 36 (3) ◽  
pp. 261-268 ◽  
Author(s):  
Mei Jiun Lee ◽  
Chi Siang Ong ◽  
Woei Jye Lau ◽  
Be Cheer Ng ◽  
Ahmad Fauzi Ismail ◽  
...  
Keyword(s):  
Uv Irradiation ◽  
Exposure Time ◽  
Composite Membrane ◽  
Polyvinylidene Fluoride ◽  
Uv Light ◽  
Irradiation Time ◽  
Uv Exposure ◽  
Polymeric Membrane ◽  
Permeate Flux ◽  
Wastewater Treatment Process

Abstract In this work, an attempt was made to evaluate the effects of ultraviolet (UV) irradiation period on the intrinsic and separation properties of composite membrane composed of organic polyvinylidene fluoride and inorganic titanium dioxide (TiO2) nanoparticles by exposing the membrane to UV-A light for up to 250 h. The changes on membrane structural morphologies and chemical characteristics upon UV exposure were studied by field-emission scanning electron microscope and Fourier transform infrared, respectively. It was observed that some cracks and fractures were formed on the membrane outer surface when it was exposed to 120-h UV light. Further increase in UV irradiation time to 250 h had caused membrane structure to collapse, turning it into powder form. Filtration experiments showed that the permeate flux of irradiated membrane was significantly increased from 10.89 L/m2 h to 21.84 L/m2 h (>100% flux increment) while oil rejection decreased with increasing UV exposure time from 0 h to 120 h. Furthermore, the mechanical strength and thermal stability of irradiated membrane were also reported to decrease with increasing UV exposure time, suggesting the negative impacts of UV light on the membrane overall stability. This research is of particular importance to evaluate the suitability and sustainability of polymeric membrane, which is widely considered as the host for photocatalyts and used for wastewater treatment process under UV irradiation.

scholarly journals Fabrication of Size-Controlled Metallic Nanogaps down to the Sub 3-Nm Level

2020 ◽  
Author(s):  
Sihai Luo ◽  
Andrea Mancini ◽  
Rodrigo Berté ◽  
Bård H. Hoff ◽  
Stefan A. Maier ◽  
...  
Keyword(s):  
Self Assembly ◽  
Surface Enhanced Raman Spectroscopy ◽  
High Yield ◽  
Large Area ◽  
Practical Applications ◽  
Molecular Diodes ◽  
Surface Enhanced Raman ◽  
Visible Light Active ◽  
Patterning Technique ◽  
Optical Applications

Metallic nanogaps are fundamental components of nanoscale photonic and electronic devices. However, the lack of reproducible high-yield fabrication methods with nanometric control over the gap-size has hindered practical applications. Here, we report a patterning technique based on molecular self-assembly and physical peeling that allows the gap-width to be tuned over the range 3 – 30 nm and enables the fabrication of massively parallel nanogap arrays containing hundreds of millions of ring-shaped nanogaps (RSNs). The method is used here to prepare molecular diodes across sub-3-nm metallic nanogaps and to fabricate visible-light-active plasmonic substrates based on large-area, gold-based RSN arrays. The substrates are applicable to a broad range of optical applications, and are used here as substrates for surface-enhanced Raman spectroscopy (SERS), providing high enhancement factors of up to 3e8 relative to similar, gap-free thin gold films.

Controlled Vapor Growth and Nonlinear Optical Applications of Large-Area 3R Phase WS2 and WSe2 Atomic Layers

2019 ◽  
Vol 29 (11) ◽  
pp. 1806874 ◽  
Author(s):  
Zhouxiaosong Zeng ◽  
Xingxia Sun ◽  
Danliang Zhang ◽  
Weihao Zheng ◽  
Xiaopeng Fan ◽  
...  
Keyword(s):  
Nonlinear Optical ◽  
Large Area ◽  
Vapor Growth ◽  
Optical Applications ◽  
Nonlinear Optical Applications

Effects of UV Exposure Time on Nanofiber Wound Dressing Properties During Sterilization

2019 ◽  
Vol 15 (3) ◽  
pp. 325-332 ◽  
Author(s):  
Serdar Tort ◽  
Fatmanur Tuğcu Demiröz ◽  
Sulhiye Yıldız ◽  
Füsun Acartürk
Keyword(s):  
Exposure Time ◽  
Wound Dressing ◽  
Uv Exposure
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