scholarly journals Meander Thin-Film Biosensor Fabrication to Investigate the Influence of Structural Parameters on the Magneto-Impedance Effect

Sensors ◽  
2021 ◽  
Vol 21 (19) ◽  
pp. 6514
Author(s):  
Abkar Sayad ◽  
Shah Mukim Uddin ◽  
Jianxiong Chan ◽  
Efstratios Skafidas ◽  
Patrick Kwan
Keyword(s):  
Thin Film ◽  
Film Thickness ◽  
Structural Parameters ◽  
High Sensitivity ◽  
Size Ratio ◽  
Optimal Ratio ◽  
Highly Sensitive ◽  
Fabrication Parameters ◽  
Significant Attention

Thin-film magneto-impedance (MI) biosensors have attracted significant attention due to their high sensitivity and easy miniaturization. However, further improvement is required to detect weak biomagnetic signals. Here, we report a meander thin-film biosensor preparation to investigate the fabrication parameters influencing the MI effect. Specifically, we hypothesized that an optimal film thickness and sensing area size ratio could be achieved to obtain a maximum MI ratio. A meander multilayer MI biosensor based on a NiFe/Cu/NiFe thin-film was designed and fabricated into 3-, 6-, and 9-turn models with film thicknesses of 3 µm and 6 µm. The 9-turn biosensor resembled the largest sensing area, while the 3- and 6-turn biosensors were designed with identical sensing areas. The results indicated that the NiFe film thickness of 6 µm with a sensing area size of 14.4 mm2 resembling a 9-turn MI biosensor is the optimal ratio yielding the maximum MI ratio of 238%, which is 70% larger than the 3- and 6-turn structures. The 3- and 6-turn MI biosensors exhibited similar characteristics where the MI ratio peaked at a similar value. Our results suggest that the MI ratio can be increased by increasing the sensing area size and film thickness rather than the number of turns. We showed that an optimal film thickness to sensing area size ratio is required to obtain a high MI ratio. Our findings will be useful for designing highly sensitive MI biosensors capable of detecting low biomagnetic signals.

scholarly journals Optimization of Fiber Bragg Gratings Inscribed in Thin Films Deposited on D-Shaped Optical Fibers

Sensors ◽  
2021 ◽  
Vol 21 (12) ◽  
pp. 4056
Author(s):  
José Javier Imas ◽  
Carlos R. Zamarreño ◽  
Ignacio del Villar ◽  
Ignacio R. Matías
Keyword(s):  
Thin Film ◽  
Film Thickness ◽  
Optical Fibers ◽  
Flat Surface ◽  
Sno2 Thin Film ◽  
Thin Film Thickness ◽  
A Value ◽  
Surrounding Refractive Index ◽  
Reflected Power ◽  
Fabrication Parameters

A fiber Bragg grating patterned on a SnO2 thin film deposited on the flat surface of a D-shaped polished optical fiber is studied in this work. The fabrication parameters of this structure were optimized to achieve a trade-off among reflected power, full width half maximum (FWHM), sensitivity to the surrounding refractive index (SRI), and figure of merit (FOM). In the first place, the influence of the thin film thickness, the cladding thickness between the core and the flat surface of the D-shaped fiber (neck), and the length of the D-shaped zone over the reflected power and the FWHM were assessed. Reflected peak powers in the range from −2 dB to −10 dB can be easily achieved with FWHM below 100 pm. In the second place, the sensitivity to the SRI, the FWHM, and the FOM were analyzed for variations of the SRI in the 1.33–1.4 range, the neck, and the thin-film thickness. The best sensitivities theoretically achieved for this device are next to 40 nm/RIU, while the best FOM has a value of 114 RIU−1.

scholarly journals An Optical Fiber Fabry–Perot Pressure Sensor with Optimized Thin Microbubble Film Shaping for Sensitivity Enhancement

Coatings ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 358 ◽  
Author(s):  
Shubin Zhang ◽  
Zhenjun Shao ◽  
Jinrong Liu ◽  
Meixue Zong ◽  
Jian Shen ◽  
...  
Keyword(s):  
Thin Film ◽  
Arc Discharge ◽  
Structural Parameters ◽  
Silicon Film ◽  
Glass Tube ◽  
High Sensitivity ◽  
Single Mode ◽  
Single Mode Fiber ◽  
Fabry Perot ◽  
Micrometer Scale

A pressure-assisted arc discharge method of preparing silicon microbubbles with a glass tube was utilized for decreasing the bubble film’s thickness and improving the bubble’s uniformity. By controlling the arc discharge intensity, discharge time and the position of the fiber carefully, the thickness of the microbubble film was reduced to the micrometer scale. Later, the thin film of the microbubble was transferred to the end the single-mode-fiber/glass-tube structure, for forming the FP (Fabry–Perot) interference cavity. As the thin film is sensitive to the outer pressure, such a configuration could be used for a high-sensitive-pressure measurement. Experimental results show that the sensitivity of this FP (Fabry–Perot) cavity was 6790 pm/MPa when the outer pressure ranges from 100 to 1600 kPa, and the relationship between the structural parameters of the thin film and the outer pressure was theoretically analyzed. Moreover, this special structure made of the end silicon film microbubble is more suitable for high-sensitivity applications.

scholarly journals Nanoporous fluorescent sensor based on upconversion nanoparticles for the detection of dichloromethane with high sensitivity

RSC Advances ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 565-571
Author(s):  
Haiyan Wang ◽  
Shiping Zhan ◽  
Xiaofeng Wu ◽  
Lingqiong Wu ◽  
Yunxin Liu
Keyword(s):  
Thin Film ◽  
Gas Sensor ◽  
Fluorescent Sensor ◽  
High Sensitivity ◽  
Anodic Alumina ◽  
Upconversion Nanoparticles ◽  
Core Shell ◽  
Highly Sensitive ◽  
Anodic Alumina Oxide ◽  
Alumina Oxide

We report a highly sensitive nanoporous fluorescence sensor based on core/shell upconversion nanoparticles (UCNPs) for the detection of dichloromethane. UCNPs are deposited on porous anodic alumina oxide templates to form a thin film-like gas sensor.

Turning electrical switching behaviors in WOx thin films by thickness

2019 ◽  
Vol 12 (01) ◽  
pp. 1850107
Author(s):  
Weijie Duan
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Film Thickness ◽  
Resistive Switching ◽  
Switching Behavior ◽  
Dynamic Evolution ◽  
Behavior Changes ◽  
Electrical Switching ◽  
Threshold Switching ◽  
Highly Sensitive

The tunability of electrical switching behaviors in WOx thin films were investigated in this paper. Electrical responses of the WOx films were observed to be highly sensitive to the film thickness. As the film thickness increases from 50 to 100[Formula: see text]nm, the switching behavior changes from complementary resistive switching (CRS) to threshold switching (TS). A defect-related dynamic evolution of filament is responsible for the switching behavior. Such a controllable electrical switching can well broaden the application of the WOx thin film.

High-sensitivity detection of gold labels by high-angle dark-field STEM imaging

1990 ◽  
Vol 48 (3) ◽  
pp. 892-893 ◽  
Author(s):  
Max T. Otten
Keyword(s):  
High Sensitivity ◽  
Dark Field ◽  
Bright Field ◽  
Backscattered Electron Imaging ◽  
Backscattered Electrons ◽  
Average Atomic Number ◽  
Highly Sensitive ◽  
Backscattered Electron ◽  
Electron Imaging ◽  
High Sensitivity Detection

Labelling of antibodies with small gold probes is a highly sensitive technique for detecting specific molecules in biological tissue. Larger gold probes are usually well visible in TEM or STEM Bright-Field images of unstained specimens. In stained specimens, however, the contrast of the stain is frequently the same as that of the gold labels, making it virtually impossible to identify the labels, especially when smaller gold labels are used to increase the sensitivity of the immunolabelling technique. TEM or STEM Dark-Field images fare no better (Figs. 1a and 2a), again because of the absence of a clear contrast difference between gold labels and stain.Potentially much more useful is backscattered-electron imaging, since this will show differences in average atomic number which are sufficiently large between the metallic gold and the stains normally used. However, for the thin specimens and at high accelerating voltages of the STEM, the yield of backscattered electrons is very small, resulting in a very weak signal. Consequently, the backscattered-electron signal is often too noisy for detecting small labels, even for large spot sizes.

High Sensitivity pH Sensors based on Amorphous Indium-gallium-zinc Oxide Thin-film Transistors

2015 ◽  
Vol 135 (6) ◽  
pp. 192-198 ◽  
Author(s):  
Shinnosuke Iwamatsu ◽  
Yutaka Abe ◽  
Toru Yahagi ◽  
Seiya Kobayashi ◽  
Kazushige Takechi ◽  
...  
Keyword(s):  
Thin Film ◽  
Zinc Oxide ◽  
Thin Film Transistors ◽  
High Sensitivity ◽  
Oxide Thin Film ◽  
Indium Gallium Zinc Oxide ◽  
Ph Sensors ◽  
Zinc Oxide Thin Film ◽  
Indium Gallium

scholarly journals Role of MRI evaluation in acute secondary inability to walk in children

2021 ◽  
Vol 52 (1) ◽  
Author(s):  
K. H. Sedeek ◽  
K. Aboualfotouh ◽  
S. M. Hassanein ◽  
N. M. Osman ◽  
M. H. Shalaby
Keyword(s):  
Transverse Myelitis ◽  
High Sensitivity ◽  
Acute Disseminated Encephalomyelitis ◽  
Limb Weakness ◽  
Non Invasive ◽  
Highly Sensitive ◽  
Common Causes ◽  
Bilateral Lower Limb ◽  
Severity Of The Disease

Abstract Background Acute bilateral lower limb weakness is a common problem in children which necessitates a rapid method for diagnosis. MRI is a non-invasive imaging technique that produces high-quality images of the internal structure of the brain and spinal cord. Results MRI was very helpful in reaching rapid and prompt diagnosis in children with acute inability to walk. Acute disseminated encephalomyelitis (ADEM), Guillain–Barré syndrome (GBS), and acute transverse myelitis (ATM) were the most common causes in our study. MRI proved to be of high sensitivity in detecting the lesions and reaching the diagnosis in ADEM and GBS; however, there was no significant relation between the lesions’ size, enhancement pattern, and severity of the disease or prognosis, yet in ATM the site of the lesion and number of cord segment affection were significantly related to the severity of the disease and prognosis. Conclusion MRI is a quick tool to reach the diagnosis of children with acute secondary inability to walk, and to eliminate other differential diagnosis which is essential for proper treatment and rapid full recovery. It is highly sensitive in detecting the lesions, their site and size.

scholarly journals Plasmon-Enhanced Sunlight Harvesting in Thin-Film Solar Cell by Randomly Distributed Nanoparticle Array

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1380
Author(s):  
Marwa M. Tharwat ◽  
Ashwag Almalki ◽  
Amr M. Mahros
Keyword(s):  
Thin Film ◽  
Solar Cells ◽  
Solar Cell ◽  
Near Infrared ◽  
Structural Parameters ◽  
Visible Region ◽  
Nanoparticle Array ◽  
Solar Energy Harvesting ◽  
Infra Red ◽  
Crucial Parameter

In this paper, a randomly distributed plasmonic aluminum nanoparticle array is introduced on the top surface of conventional GaAs thin-film solar cells to improve sunlight harvesting. The performance of such photovoltaic structures is determined through monitoring the modification of its absorbance due to changing its structural parameters. A single Al nanoparticle array is integrated over the antireflective layer to boost the absorption spectra in both visible and near-infra-red regimes. Furthermore, the planar density of the plasmonic layer is presented as a crucial parameter in studying and investigating the performance of the solar cells. Then, we have introduced a double Al nanoparticle array as an imperfection from the regular uniform single array as it has different size particles and various spatial distributions. The comparison of performances was established using the enhancement percentage in the absorption. The findings illustrate that the structural parameters of the reported solar cell, especially the planar density of the plasmonic layer, have significant impacts on tuning solar energy harvesting. Additionally, increasing the plasmonic planar density enhances the absorption in the visible region. On the other hand, the absorption in the near-infrared regime becomes worse, and vice versa.

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