The Experts below are selected from a list of 15660 Experts worldwide ranked by ideXlab platform
Francisco J. Arregui - One of the best experts on this subject based on the ideXlab platform.
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Optical Fiber resonance-based pH sensors using gold nanoparticles into polymeric layer-by-layer coatings
Microsystem Technologies, 2016Co-Authors: Pedro J. Rivero, Miguel Hernaez, Ignacio R. Matias, Javier Goicoechea, Abian B. Socorro, Francisco J. ArreguiAbstract:The development of new nanocoatings onto Optical Fiber Core is a hot topic within the Optical Fiber devices. The possibility of fabricating hybrid nanocoatings based on inorganic (gold nanoparticles, AuNPs) and organic materials (polymeric structure) can be performed using the layer-by-layer embedding deposition technique. The deposition of a nanostructure coating onto an Optical Fiber Core has been performed in order to obtain Optical Fiber resonance-based pH sensors. The incorporation of gold nanoparticles (AuNPs) into polymeric thin films has been confirmed by atomic force microscopy, scanning electron microscopy and UV---Vis spectroscopy. In addition, two electromagnetic resonances known as localized surface plasmon resonance (LSPR) or lossy mode resonance (LMR), can be generated as a function of the resultant thickness coating. In this work, the fabrication of a dual LSPR-LMR Optical Fiber pH sensor is presented where the LSPR is used as a reference signal and the LMR is used as a sensing band due to the great difference in their corresponding sensitivities to pH changes of the surrounding medium. It has been demonstrated that LMR improves the sensitivity of the LSPR band in more than one hundred times. The device shows a high sensitivity, fast response time and large dynamical range of 134.7 nm from pH 4.0 to pH 6.0.
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Optical Fiber humidity sensors based on localized surface plasmon resonance lspr and lossy mode resonance lmr in overlays loaded with silver nanoparticles
Sensors and Actuators B-chemical, 2012Co-Authors: Pedro J. Rivero, Javier Goicoechea, Aitor Urrutia, Francisco J. ArreguiAbstract:Abstract In this work, it is presented for the first time the fabrication and characterization of a novel Optical Fiber humidity sensor based on both Lossy-mode resonance (LMR) and Localized Surface Plasmon Resonance (LSPR). Those resonances were created using Layer-by-Layer (LbL) polymeric coating loaded with Ag nanoparticles (Ag NPs) and fabricated onto an Optical Fiber Core. Firstly, it was observed a LSPR attenuation band, inherent to the presence of the Ag NPs in the coating. This LSPR band showed a slight intensity variation with Relative Humidity (RH) changes but no significant wavelength dependence was observed. Otherwise several LMR attenuation bands were observed in the 400–1100 nm spectral range as the thickness coating was increased. The LMR maxima depend strongly on the thickness and refractive index of the LbL overlay, and therefore, they show a strong wavelength response to Relative Humidity (RH) changes. A wavelength-based Optical humidity sensor was achieved and the dynamic range (42.4 nm), transfer function, response time (476 ms and 447 ms for rise/fall respectively) were characterized. The results confirm that this sensor could be used even for monitoring human breathing.
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Optical Fiber Refractometers based on Indium Tin Oxide Coatings with Response in the Visible Spectral Region
Procedia Engineering, 2012Co-Authors: Carlos R. Zamarreño, S. Lopez, Miguel Hernaez, I. Del Villar, Ignacio R. Matias, Francisco J. ArreguiAbstract:Abstract This work presents the fabrication of Optical Fiber refractometers based on indium tin oxide (ITO) coatings with response in the visible spectral region. ITO thin-films have been sputtered by employing a rotating mechanism that enables the fabrication of smooth homogeneous coatings onto the Optical Fiber Core. The ITO coated Optical Fiber devices present several resonances in the visible and infra-red region. These resonances show high Optical power attenuations (more than 10 dB) in the visible spectral region, which produces changes in the colour of the output visible light. Therefore, since these resonances shift as a function of the surrounding medium refractive index (SMRI), it is feasible to determine the refractive index of the outer medium in contact with the ITO coating by simply monitoring the chromatic coordinates of the visible output light.
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Optical Fiber ph sensor based on lossy mode resonances by means of thin polymeric coatings
Sensors and Actuators B-chemical, 2011Co-Authors: Carlos R. Zamarreño, Miguel Hernaez, Ignacio R. Matias, I Del Villar, Francisco J. ArreguiAbstract:Abstract This work describes the fabrication of an Optical Fiber sensor with spectral response to pH based on the deposition of a thin polymeric coating on an Optical Fiber Core. If the thin polymeric coating has a high refractive index real part and a non-null imaginary part, this permits a coupling of light to the modes guided in the polymeric coating originating Optical resonances. These resonances are named by some authors as lossy-mode resonances (LMR) or guided-mode resonances. Moreover, the location of the resonances in the Optical spectrum varies as a function of the coating thickness and refractive index. Hence, the utilization of the well-known poly(allylamine hydrochloride) (PAH) and poly(acrylic acid) (PAA) pH sensitive polymeric coating that presents a variation of the thickness with the pH of the solution (known as swelling/deswelling behaviour) permits the fabrication of Optical Fiber pH sensors based on wavelength detection. The fabrication of ready-to-use devices requires considering several aspects such as the adequate polymeric coating thickness or the selection of the resonance to be monitored. As a result, LMR-based Optical Fiber pH sensors with accuracy of ±0.001 pH units and an average sensitivity of 0.027 pH units/nm within the range between pH 3 and pH 6 have been obtained after an adequate design.
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Humidity sensor based on silver nanoparticles embedded in a polymeric coating
2011 Fifth International Conference on Sensing Technology, 2011Co-Authors: Pedro J. Rivero, Francisco J. Arregui, Javier Goicoechea, Aitor Urrutia, Ignacio R. MatiasAbstract:In this work, a new humidity sensor based on the deposition of silver nanoparticles embedded in a polymeric coating on an Optical Fiber Core is presented. The silver nanoparticles inside the coating were characterized by transmission electron microscopy (TEM) in order to get additional information about their size and shape. An increase of the Surface Plasmon Resonance (SPR) peak intensity is observed when the coating is built up by using the Layer-by-Layer (LbL) deposition technique. Changes in Relative Humidity from 20% to 80% are detected by a shift of the SPR wavelength.
Weixuan Jing - One of the best experts on this subject based on the ideXlab platform.
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Hydrothermal fabrication of ZnO nanorod-based grating patterns with arrays of Optical Fiber Cores as templates
Superlattices and Microstructures, 2015Co-Authors: Weixuan Jing, Zhuangde Jiang, Jiafan Shi, Fan Zhou, Yanyan Cheng, Kun GaoAbstract:Abstract A hydrothermal fabrication of ZnO nanorod-based grating patterns on Si substrates is reported. The arrays of Optical Fiber Cores were manually assembled as templates with nominal pitches of 250 μm and 375 μm. The profiles of the templates and the grating patterns were extracted and quantitatively characterized based on micrographs of scanning electron microscopy (SEM) and Image Processing Toolbox of MATLAB. The errors of the actual pitches and the parallelism demonstrate that the process capability of manually assembling the Optical Fiber Cores can meet the quality requirement of the templates. The critical dimensions (CDs) show that the size of the trough formed by the template and the Si substrate determines the location of the grating pattern. The characteristic parameters, including line edge roughness (LER), line width roughness (LWR), skewness (Sk), kurtosis (Ku), and correlation length (ζ), exhibit that the three-phase contact lines among the trapped air bubble, ZnO seed solution, and Si substrate (or the Optical Fiber Core) decide the form of the grating pattern. The research found that larger nominal pitch of the template resulted in larger size of the trough which further led to less CD, and higher hydrophilicity of the Si surfaces resulted in smoother profiles whilst lower hydrophilicity of the Optical Fiber Core surfaces led to rougher ones.
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Effects of the geometries of micro-scale substrates on the surface morphologies of ZnO nanorod-based hierarchical structures
Applied Surface Science, 2015Co-Authors: Weixuan Jing, Zhuangde Jiang, Jiafan Shi, Fan Zhou, Yanyan Cheng, Kun GaoAbstract:Abstract This paper identifies and investigates the influencing factors and their effects on the surface morphologies of ZnO nanorod-based hierarchical structures. With ZnO nanorods hydrothermally synthesized on a piece of planar glass, an Optical Fiber Core, and a SiO 2 microsphere, three kinds of ZnO nanorod-based hierarchical structures were fabricated. It is found that not only the synthesizing parameters but also the geometries of the micro-scale substrates affect significantly the nucleation densities of seed layers and the Zn 2+ diffusion zones of growth solution upon the substrate surfaces. These two factors further give rise to varied diameters and orientation of the ZnO nanorods as well as different sizes of the pits among the bundles of ZnO nanorods, which eventually result in different surface morphologies of corresponding hierarchical structures. With Zn 2+ concentration of the growth solution increasing, side-by-side coalescence among neighboring ZnO nanorods first appears on the Optical Fiber Core. The different curvature radii of the Optical Fiber Core at front and side view lead to the anisotropic surface morphology of the related hierarchical structure. Although their curvature radii are the same, the different geometries of the Optical Fiber Core at side view and the planar glass account for varied surface morphologies of the corresponding hierarchical structures.
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Construction of 3D Arrays of Cylindrically Hierarchical Structures with ZnO Nanorods Hydrothermally Synthesized on Optical Fiber Cores
Journal of Nanomaterials, 2014Co-Authors: Weixuan Jing, Zhuangde Jiang, Jiafan Shi, Fan Zhou, Yanyan ChengAbstract:With ZnO nanorods hydrothermally synthesized on manually assembled arrays of Optical Fiber Cores, 3D arrays of ZnO nanorod-based cylindrically hierarchical structures with nominal pitch 250 μm or 375 μm were constructed. Based on micrographs of scanning electron microscopy and image processing operators of MATLAB software, the 3D arrays of cylindrically hierarchical structures were quantitatively characterized. The values of the actual diameters, the actual pitches, and the parallelism errors suggest that the process capability of the manual assembling is sufficient and the quality of the 3D arrays of cylindrically hierarchical structures is acceptable. The values of the characteristic parameters such as roughness, skewness, kurtosis, correlation length, and power spectrum density show that the surface morphologies of the cylindrically hierarchical structures not only were affected significantly by Zn2+concentration of the growth solution but also were anisotropic due to different curvature radii of the Optical Fiber Core at side and front view.
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Simulation and ZnO nanowires-based generation of a hierarchical structure on an Optical Fiber Core
Applied Surface Science, 2013Co-Authors: Weixuan Jing, Lingling Niu, Bing Wang, Chen Lujia, Zhuangde JiangAbstract:Abstract A hierarchical structure with a random rough surface superimposed on a cylinder substrate was presented in this paper. The effect of the characteristic parameters on the surface properties of this hierarchical structure was summarized and partially simulated. The hierarchical structure was generated by synthesizing ZnO nanowires with hydrothermal method on an Optical Fiber Core. Scanning electron microscopy (SEM)-based characterization of the generated random rough surface on the Optical Fiber Core was employed to regulate and optimize synthesizing parameters of ZnO nanowires. The relationship between the synthesizing parameters and the desired morphology of the hierarchical structure was established. The results can be used to form various hierarchical structures to meet the requirements of different applications in nanotechnology domain, including the wettability and the adsorption of as well as the immobilization on different hierarchical structures.
Kun Gao - One of the best experts on this subject based on the ideXlab platform.
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Hydrothermal fabrication of ZnO nanorod-based grating patterns with arrays of Optical Fiber Cores as templates
Superlattices and Microstructures, 2015Co-Authors: Weixuan Jing, Zhuangde Jiang, Jiafan Shi, Fan Zhou, Yanyan Cheng, Kun GaoAbstract:Abstract A hydrothermal fabrication of ZnO nanorod-based grating patterns on Si substrates is reported. The arrays of Optical Fiber Cores were manually assembled as templates with nominal pitches of 250 μm and 375 μm. The profiles of the templates and the grating patterns were extracted and quantitatively characterized based on micrographs of scanning electron microscopy (SEM) and Image Processing Toolbox of MATLAB. The errors of the actual pitches and the parallelism demonstrate that the process capability of manually assembling the Optical Fiber Cores can meet the quality requirement of the templates. The critical dimensions (CDs) show that the size of the trough formed by the template and the Si substrate determines the location of the grating pattern. The characteristic parameters, including line edge roughness (LER), line width roughness (LWR), skewness (Sk), kurtosis (Ku), and correlation length (ζ), exhibit that the three-phase contact lines among the trapped air bubble, ZnO seed solution, and Si substrate (or the Optical Fiber Core) decide the form of the grating pattern. The research found that larger nominal pitch of the template resulted in larger size of the trough which further led to less CD, and higher hydrophilicity of the Si surfaces resulted in smoother profiles whilst lower hydrophilicity of the Optical Fiber Core surfaces led to rougher ones.
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Effects of the geometries of micro-scale substrates on the surface morphologies of ZnO nanorod-based hierarchical structures
Applied Surface Science, 2015Co-Authors: Weixuan Jing, Zhuangde Jiang, Jiafan Shi, Fan Zhou, Yanyan Cheng, Kun GaoAbstract:Abstract This paper identifies and investigates the influencing factors and their effects on the surface morphologies of ZnO nanorod-based hierarchical structures. With ZnO nanorods hydrothermally synthesized on a piece of planar glass, an Optical Fiber Core, and a SiO 2 microsphere, three kinds of ZnO nanorod-based hierarchical structures were fabricated. It is found that not only the synthesizing parameters but also the geometries of the micro-scale substrates affect significantly the nucleation densities of seed layers and the Zn 2+ diffusion zones of growth solution upon the substrate surfaces. These two factors further give rise to varied diameters and orientation of the ZnO nanorods as well as different sizes of the pits among the bundles of ZnO nanorods, which eventually result in different surface morphologies of corresponding hierarchical structures. With Zn 2+ concentration of the growth solution increasing, side-by-side coalescence among neighboring ZnO nanorods first appears on the Optical Fiber Core. The different curvature radii of the Optical Fiber Core at front and side view lead to the anisotropic surface morphology of the related hierarchical structure. Although their curvature radii are the same, the different geometries of the Optical Fiber Core at side view and the planar glass account for varied surface morphologies of the corresponding hierarchical structures.
Zhuangde Jiang - One of the best experts on this subject based on the ideXlab platform.
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Hydrothermal fabrication of ZnO nanorod-based grating patterns with arrays of Optical Fiber Cores as templates
Superlattices and Microstructures, 2015Co-Authors: Weixuan Jing, Zhuangde Jiang, Jiafan Shi, Fan Zhou, Yanyan Cheng, Kun GaoAbstract:Abstract A hydrothermal fabrication of ZnO nanorod-based grating patterns on Si substrates is reported. The arrays of Optical Fiber Cores were manually assembled as templates with nominal pitches of 250 μm and 375 μm. The profiles of the templates and the grating patterns were extracted and quantitatively characterized based on micrographs of scanning electron microscopy (SEM) and Image Processing Toolbox of MATLAB. The errors of the actual pitches and the parallelism demonstrate that the process capability of manually assembling the Optical Fiber Cores can meet the quality requirement of the templates. The critical dimensions (CDs) show that the size of the trough formed by the template and the Si substrate determines the location of the grating pattern. The characteristic parameters, including line edge roughness (LER), line width roughness (LWR), skewness (Sk), kurtosis (Ku), and correlation length (ζ), exhibit that the three-phase contact lines among the trapped air bubble, ZnO seed solution, and Si substrate (or the Optical Fiber Core) decide the form of the grating pattern. The research found that larger nominal pitch of the template resulted in larger size of the trough which further led to less CD, and higher hydrophilicity of the Si surfaces resulted in smoother profiles whilst lower hydrophilicity of the Optical Fiber Core surfaces led to rougher ones.
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Effects of the geometries of micro-scale substrates on the surface morphologies of ZnO nanorod-based hierarchical structures
Applied Surface Science, 2015Co-Authors: Weixuan Jing, Zhuangde Jiang, Jiafan Shi, Fan Zhou, Yanyan Cheng, Kun GaoAbstract:Abstract This paper identifies and investigates the influencing factors and their effects on the surface morphologies of ZnO nanorod-based hierarchical structures. With ZnO nanorods hydrothermally synthesized on a piece of planar glass, an Optical Fiber Core, and a SiO 2 microsphere, three kinds of ZnO nanorod-based hierarchical structures were fabricated. It is found that not only the synthesizing parameters but also the geometries of the micro-scale substrates affect significantly the nucleation densities of seed layers and the Zn 2+ diffusion zones of growth solution upon the substrate surfaces. These two factors further give rise to varied diameters and orientation of the ZnO nanorods as well as different sizes of the pits among the bundles of ZnO nanorods, which eventually result in different surface morphologies of corresponding hierarchical structures. With Zn 2+ concentration of the growth solution increasing, side-by-side coalescence among neighboring ZnO nanorods first appears on the Optical Fiber Core. The different curvature radii of the Optical Fiber Core at front and side view lead to the anisotropic surface morphology of the related hierarchical structure. Although their curvature radii are the same, the different geometries of the Optical Fiber Core at side view and the planar glass account for varied surface morphologies of the corresponding hierarchical structures.
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Construction of 3D Arrays of Cylindrically Hierarchical Structures with ZnO Nanorods Hydrothermally Synthesized on Optical Fiber Cores
Journal of Nanomaterials, 2014Co-Authors: Weixuan Jing, Zhuangde Jiang, Jiafan Shi, Fan Zhou, Yanyan ChengAbstract:With ZnO nanorods hydrothermally synthesized on manually assembled arrays of Optical Fiber Cores, 3D arrays of ZnO nanorod-based cylindrically hierarchical structures with nominal pitch 250 μm or 375 μm were constructed. Based on micrographs of scanning electron microscopy and image processing operators of MATLAB software, the 3D arrays of cylindrically hierarchical structures were quantitatively characterized. The values of the actual diameters, the actual pitches, and the parallelism errors suggest that the process capability of the manual assembling is sufficient and the quality of the 3D arrays of cylindrically hierarchical structures is acceptable. The values of the characteristic parameters such as roughness, skewness, kurtosis, correlation length, and power spectrum density show that the surface morphologies of the cylindrically hierarchical structures not only were affected significantly by Zn2+concentration of the growth solution but also were anisotropic due to different curvature radii of the Optical Fiber Core at side and front view.
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Simulation and ZnO nanowires-based generation of a hierarchical structure on an Optical Fiber Core
Applied Surface Science, 2013Co-Authors: Weixuan Jing, Lingling Niu, Bing Wang, Chen Lujia, Zhuangde JiangAbstract:Abstract A hierarchical structure with a random rough surface superimposed on a cylinder substrate was presented in this paper. The effect of the characteristic parameters on the surface properties of this hierarchical structure was summarized and partially simulated. The hierarchical structure was generated by synthesizing ZnO nanowires with hydrothermal method on an Optical Fiber Core. Scanning electron microscopy (SEM)-based characterization of the generated random rough surface on the Optical Fiber Core was employed to regulate and optimize synthesizing parameters of ZnO nanowires. The relationship between the synthesizing parameters and the desired morphology of the hierarchical structure was established. The results can be used to form various hierarchical structures to meet the requirements of different applications in nanotechnology domain, including the wettability and the adsorption of as well as the immobilization on different hierarchical structures.
Banshi Dhar Gupta - One of the best experts on this subject based on the ideXlab platform.
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fabrication and characterization of a surface plasmon resonance based Fiber optic sensor using gel entrapment technique for the detection of low glucose concentration
Sensors and Actuators B-chemical, 2013Co-Authors: Sarika Singh, Banshi Dhar GuptaAbstract:Abstract In this paper we report the fabrication and characterization of a surface plasmon resonance (SPR) based Fiber optic sensor, working on wavelength interrogation method, to measure the low glucose concentration (similar to the human blood) in aqueous fluid. The sensing probe is prepared by coating of films of silver and silicon on the Optical Fiber Core followed by immobilization of enzyme (glucose oxidase) using gel entrapment method. Experimental results on SPR spectra show a blue shift in the resonance wavelength on increase in the concentration of the glucose in samples. Further, the sensitivity of the sensor decreases as the concentration of the glucose increases whereas the detection accuracy is almost independent of the glucose concentration. In addition, for 80 mg/dL glucose concentration, the influence of pH of the sample on the performance of the sensor has been studied in terms of sensitivity and detection accuracy. The results show that the optimum working pH range for the sensor is around pH 7 (close to blood pH 7.4). The sensor operates in the glucose concentration range of 0–260 mg/dL. Since the optimum performance and operating range of the sensor fall in the physiological range of human blood glucose it may find application in biomedical sciences. The other advantages are high sensitivity, glucose selectivity, stability and short response time of the sensor.
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Localized Surface Plasmon Resonance-Based Fiber Optic U-Shaped Biosensor for the Detection of Blood Glucose
Plasmonics, 2012Co-Authors: Sachin K. Srivastava, Vikas Arora, Sameer Sapra, Banshi Dhar GuptaAbstract:In the present study, we report the first Fiber optic glucose sensor utilizing localized surface plasmon resonance of metal nanoparticles. The Fiber was bent in the form of a U-shaped probe for point detection and sensitivity enhancement. The probe was prepared by first attaching gold nanoparticles on the Optical Fiber Core and then immobilizing glucose oxidase over it. The sensor operates in the intensity modulation scheme in which the absorbance is measured with respect to the changes in the glucose concentration. The presence of glucose in the vicinity of the sensing region changes the refractive index of the film due to the chemical reactions with glucose oxidase. The absorbance of the metal nanoparticle changes significantly due to local refractive index change. The Fiber optic U-shaped probes of different bending radii were fabricated and it has been found that the probe with bending radius around 0.982 mm possesses the maximum sensitivity. The response of the sensor is fast and requires very small volume of sensing sample (∼150 μl) which makes it more suitable for commercialization and better than present commercial sensors, which require about 1.5 ml of blood for the detection of glucose.