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Article
Publication date: 13 April 2015

Deliang Liu, Shuhua Cao and Jiujun Xu

The purpose of this paper is to establish a rapid and effective numerical model of thin film lubrication with clear physical conception, in which viscosity variation along…

Abstract

Purpose

The purpose of this paper is to establish a rapid and effective numerical model of thin film lubrication with clear physical conception, in which viscosity variation along the direction of film thickness was used instead of average viscosity, and continuous Reynolds equation was used in the calculation of thin film lubrication.

Design/methodology/approach

Based on rheology and thin film lubrication with point contact and considering features of shear thinning and like-solidification of lubricant oil in the thin film lubrication state, a modified formula with overall average equivalent viscosity was proposed by combining numerical calculation and experiment data.

Findings

It is a fast and efficient method for film lubrication state simulation.

Research limitations/implications

Thin film lubrication research on a nanoscale is very popular, and a variety of thin film lubrication models are proposed. Due to the complexity of thin film lubrication, it is still in the stage of revealing law and establishing calculation model.

Originality/value

The key issue is how to obtain the viscosity correction formula derived from engineering practice, also considered the lubricating oil class solidification and shear-thinning properties on thin film lubrication, while based on the system experiment, the viscosity modified formula for the gap, speed changes are proposed to obtain the overall average equivalent viscosity which makes the thin film lubrication micro to macro, so that a clear physical meaning for thin-film lubrication numerical calculation model is established.

Details

Industrial Lubrication and Tribology, vol. 67 no. 3
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 1 January 1986

S. Nørlyng

This paper gives a popular introduction to thin film and some reasons for using this technology. The miniaturisation techniques at Brel & Kjaer are described and the…

Abstract

This paper gives a popular introduction to thin film and some reasons for using this technology. The miniaturisation techniques at Brel & Kjaer are described and the background for the work with thin film techniques is given. The company's method of realising thin film circuits is described by going through the resistor materials, resistor design and photolithography and etching steps. The kind of equipment needed and what B & K use to make prototypes and small scale production are shown. TCR‐values and the resistor stability after 10,000 hours at different environmental exposures are given. Examples of applications with single layer and double layer structures are shown. A thick film circuit is transformed to thin film, and the size reduction can be seen. Finally, for this circuit, the cost calculations are stated for both versions.

Details

Microelectronics International, vol. 3 no. 1
Type: Research Article
ISSN: 1356-5362

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Article
Publication date: 1 January 2008

B.B. Vhanakhande, S.V. Jadhav and Vijaya Puri

The purpose of this paper is to compare thick and thin film microstripline response to conducting overlay.

Abstract

Purpose

The purpose of this paper is to compare thick and thin film microstripline response to conducting overlay.

Design/methodology/approach

Study changes in transmission and reflection of both thick and thin film microstripline due to overlay of polyaniline (PANI) thin film on stainless steel and silver. PANI was deposited by electropolymerisation method using HCl and H2SO4.

Findings

Transmittance of both the thick and thin film microstripline decreases due to the PANI overlay and reflectance increases. Thin film microstripline is more sensitive to the type of conducting overlay than thick film microstripline. PANI deposited on silver is more absorbing than PANI deposited on stainless steel using HCl acid. The overlay makes the response of the microstripline more dispersive.

Originality/value

The increase in reflectance and decrease in transmittance can provide information about the type of overlay materials. There is need for newer materials which can replace traditional metals for microstrip components. PANI might serve this purpose.

Details

Microelectronics International, vol. 25 no. 1
Type: Research Article
ISSN: 1356-5362

Keywords

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Article
Publication date: 7 December 2020

Michał Mazur, Roman Pastuszek, Damian Wojcieszak, Danuta Kaczmarek, Jarosław Domaradzki, Agata Obstarczyk and Aneta Lubanska

Indium tin oxide (ITO) is a material belonging to the group of transparent conductive oxides, which are widely used in many fields of technology including optoelectronics…

Abstract

Purpose

Indium tin oxide (ITO) is a material belonging to the group of transparent conductive oxides, which are widely used in many fields of technology including optoelectronics and photovoltaics. However, the properties of ITO thin films depend on many factors. Therefore, the aim of the study was thorough investigation of the properties of sputtered ITO thin films of various thicknesses.

Design/methodology/approach

ITO coatings were deposited by magnetron sputtering in pure argon atmosphere using ceramic ITO target. Various deposition times resulted in obtaining thin films with different thickness, which had significant influence on the optoelectronic properties of deposited coatings. In this work the results of investigation of structural, surface, optical and electrical properties were presented.

Findings

Increase of the coating thickness caused change of the microstructure from amorphous to nanocrystalline and occurrence of grains with a size of 40 to 60 nm on their surface. Moreover, the fundamental absorption edge was red-shifted, whereas the average transmission in the visible wavelength range remained similar. Increase of the thickness caused considerable decrease of the sheet resistance and resistivity. It was found that even thin films with a thickness of 10 nm had antistatic properties.

Originality/value

The novelty and originality of presented work consists in, among other, determination of antistatic properties of ITO thin films with various sheet resistances that are in the range typical for dielectric and semiconducting material. To date, there are no reports on such investigations in the literature. Reported findings might be very helpful in the case of, for example, construction of transparent antireflective and antistatic multilayers.

Details

Circuit World, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0305-6120

Keywords

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Article
Publication date: 13 April 2015

Elias P. Koumoulos, Vasiliki P. Tsikourkitoudi, Ioannis A. Kartsonakis, Vassileios E. Markakis, Nikolaos Papadopoulos, Evangelos Hristoforou and Costas A. Charitidis

The purpose of this paper is to produce cobalt (Co)-based thin films by metalorganic chemical vapor deposition (CVD) technique and then to evaluate structural and…

Abstract

Purpose

The purpose of this paper is to produce cobalt (Co)-based thin films by metalorganic chemical vapor deposition (CVD) technique and then to evaluate structural and mechanical integrity.

Design/methodology/approach

Co-based thin films were produced by metalorganic CVD technique. Boronizing, carburization and nitridation of the produced Co thin films were accomplished through a post-treatment stage of thermal diffusion into as-deposited Co thin films, in order to produce cobalt boride (Co2B), cobalt carbide and cobalt nitride thin films in the surface layer of Co. The surface topography and the crystal structure of the produced thin films were evaluated through scanning electron microscopy and X-ray diffraction, respectively. The mechanical integrity of the produced thin films was evaluated through nanoindentation technique.

Findings

The obtained results indicate that Co2B thin film exhibits the highest nanomechanical properties (i.e. H and E), while Co thin film has enhanced plasticity. The cobalt oxide thin film exhibits higher resistance to wear in comparison to the cobalt thin film, a fact that is confirmed by the nanoscratch analysis showing lower coefficient of friction for the oxide.

Originality/value

This work is original.

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Article
Publication date: 5 January 2015

N.F. Lokman, F. Suja', H. Abdullah and A.A. Abu Bakar

This purpose of this study is to investigate the structural and morphology of hybrid silver-crosslinked chitosan thin films potentially for surface plasmon resonance (SPR…

Abstract

Purpose

This purpose of this study is to investigate the structural and morphology of hybrid silver-crosslinked chitosan thin films potentially for surface plasmon resonance (SPR) sensor application. Silver, silver-chitosan and silver-crosslinked chitosan (annealed) thin films also were prepared as controls for this study.

Design/methodology/approach

Silver was firstly coated on top of the glass substrate by magnetron sputtering method. Different chitosan solutions (with and without glutaraldehyde) were coated on top of the substrate by spin coating method. Annealing treatment was carried out for one of silver-crosslink chitosan sample. The structural and morphology of all the thin films were studied by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and atomic force microscopy (AFM). The SPR curves also were measured by the SPR sensor with air and deionised (DI) water as analytes.

Findings

The structure of silver-crosslinked chitosan thin film presented a monoclinic structure with high crystallinity of 131.71 nm at the prominent peak by XRD analysis. The FESEM and AFM analyses revealed the morphology to be rough in surface attributed to enhanced contact with analytes in SPR measurement compared to other thin films.

Research limitations/implications

In the present study, the glutaraldehyde used to crosslink the thin film increased hydrophobicity and allows for more binding capacity.

Originality/value

The proposed silver-crosslinked chitosan thin film may prove beneficial for biosensing such as in environmental applications by SPR sensor.

Details

Pigment & Resin Technology, vol. 44 no. 1
Type: Research Article
ISSN: 0369-9420

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Article
Publication date: 18 May 2021

Kesavan Devarayan, Padmavathi P. and Kopperundevi Sivakami Nagaraju

Development of thin film sensors with pH function for noninvasive real-time monitoring of spoilage of packed seafood such as fish, crab and shrimp are described in this…

Abstract

Purpose

Development of thin film sensors with pH function for noninvasive real-time monitoring of spoilage of packed seafood such as fish, crab and shrimp are described in this study. It is also the purpose of this study to enhance the leaching resistance of the sensors by using a suitable strategy and to quantitatively correlate the sensor’s halochromism with the total volatile amine.

Design/methodology/approach

To prepare halochromic sensors with better leaching resistance, biocompatible materials such as starch, agar, polyvinyl alcohol and cellulose acetate along with a halochromic dye were used to prepare the thin film sensors. These thin films were evaluated for monitoring the spoilage of packed seafood at room temperature, 4°C and −2°C up to 30 days. The halochromic sensors were characterized using UV-visible and FT-IR spectroscopy.

Findings

CIELab analyses of the halochromism of the thin film sensors revealed that the color changes exhibited by the sensors in response to the spoilage of seafood are visually distinguishable. Further, the halochromic response of the thin films was directly proportional to the amount of total volatile base nitrogen that evolved from the packed seafood. Excellent leaching resistance was observed for the developed thin film sensors. The halochromic property of the sensors is reversible and thus the sensors are recyclable. Besides, the thin film sensors exhibited significant biodegradability.

Originality/value

This study provides insights for use of different biocompatible polymers for obtaining enhanced leaching resistance in halochromic sensors. Further, the color changes exhibited by the sensors are in line with the total volatile amines evolved from the packed seafood. These results highlight the importance of the developed halochromic thin film sensors for real-time monitoring of the spoilage of packed seafood.

Details

Pigment & Resin Technology, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0369-9420

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Article
Publication date: 1 April 1998

Gerhard Klink and Andreas Drost

Coating and lithography steps in thinfilm processing require planar and smooth surfaces. Usually ceramic substrates with as‐fired surface roughness of Ra < 0.1µm or with…

Abstract

Coating and lithography steps in thinfilm processing require planar and smooth surfaces. Usually ceramic substrates with as‐fired surface roughness of Ra < 0.1µm or with polished surfaces for advanced requirements are used. In general, a thick‐film hybrid has an inappropriate surface for further successful thinfilm processing. In this work, the influence of surface roughness and topography on the properties of thinfilm conductors and the fabrication of vias is investigated. Surface smoothing and local planarisation can be achieved by the use of a thick‐film overglaze or by coating the surface with polyimide prior to thinfilm processing. The improvements in conductor and via yield are measured by adequate test structures with a conductor width of 25µm. Based on the results, a process is given to provide a thick‐film multilayer with a sufficient smooth and planar surface suitable for thinfilm processes.

Details

Microelectronics International, vol. 15 no. 1
Type: Research Article
ISSN: 1356-5362

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Article
Publication date: 29 June 2020

Dinesh Ramkrushna Rotake, Anand Darji and Jitendra Singh

The purpose of this paper is a new thin-film based sensor proposed for sensitive and selective detection of mercury (Hg2+) ions in water. The thin-film platform is easy to…

Abstract

Purpose

The purpose of this paper is a new thin-film based sensor proposed for sensitive and selective detection of mercury (Hg2+) ions in water. The thin-film platform is easy to use and quick for heavy metal ions (HMIs) detection in the picomolar range. Ion-selective self-assembled monolayer's (SAM) of thiol used for the detection of HMIs above the Au/Ti top surface.

Design/methodology/approach

A thin-film based platform is suitable for the on-field experiments and testing of water samples. HMIs (antigen) and thiol-based SAM (antibody) interaction results change in surface morphology and topography. In this study, the authors have used different characterization techniques to check the selectivity of the proposed method. This change in the morphology and topography of thin-film sensor checked with Fourier-transform infrared spectroscopy, surface-enhanced Raman scattering spectroscopy, atomic force microscopy and scanning electron microscopy with energy dispersive x-ray analysis used for high-resolution images.

Findings

This thin-film based platform is straightforward to use and suitable for real-time detection of HMIs at the picomolar range. This thin-film based sensor platform capable of achieving a lower limit of detection (LOD) 27.42 ng/mL (136.56 pM) using SAM of Homocysteine-Pyridinedicarboxylic acid to detect Hg2+ ions.

Research limitations/implications

A thin-film based technology is perfect for real-time testing and removal of HMIs, but the LOD is higher as compared to microcantilever-based devices.

Originality/value

The excessive use and commercialization of nanoparticle (NPs) are quickly expanding their toxic impact on health and the environment. The proposed method used the combination of thin-film and NPs, to overcome the limitation of NPs-based technique and have picomolar (136.56 pM) range of HMIs detection. The proposed thin-film-based sensor shows excellent repeatability and the method is highly reliable for toxic Hg2+ ions detection. The main advantage of the proposed thin-film sensor is its ability to selectively remove the Hg2+ ions from water samples just like a filter and a sensor for detection at picomolar range makes this method best among the other current-state of the art techniques.

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Article
Publication date: 1 May 2006

Y. Zhang

To develop a more realistic model for molecularly thin film hydrodynamic lubrication by incorporating the fluid inhomogeneity and discontinuity effects across the fluid…

Abstract

Purpose

To develop a more realistic model for molecularly thin film hydrodynamic lubrication by incorporating the fluid inhomogeneity and discontinuity effects across the fluid film thickness in this lubrication.

Design/methodology/approach

The total mass flow of the fluid through the contact in a basic one‐dimensional molecularly thin film hydrodynamic lubrication is studied by incorporating the fluid inhomogeneity and discontinuity effects across the fluid film thickness, based on a simplified momentum transfer model between neighboring fluid molecules across the fluid film thickness. This flow is calculated according to the present approach and the theory of viscous flow between two contact surfaces. The total mass flow of the fluid through the contact in this lubrication is also calculated from conventional hydrodynamic lubrication theory, which was based on continuum fluid assumption in the whole lubricated contact. The ratio of this flow calculated from the present approach to that calculated from conventional hydrodynamic lubrication theory is here defined as the flow factor for a one‐dimensional molecularly thin film hydrodynamic lubrication due to the fluid inhomogeneity and discontinuity effects. Results of this flow factor are presented for wide operational parameters.

Findings

In the molecularly thin film hydrodynamic lubrication, when the fluid inhomogeneity and discontinuity across the fluid film thickness both are incorporated, the total fluid mass flow through the contact and thus the global fluid film thickness are increased. The combined effect of the fluid inhomogeneity and discontinuity across the fluid film thickness on the total fluid mass flow through the contact in this lubrication is determined by the operational parameter K=((∂p/∂xh2)/[6ηbulk(1−ξ)(ua+ub)]); when the operational parameter K is high, this effect is significant; when the operational parameter K is low, this effect is negligible. On the other hand, in this lubrication, when the combined effect of the fluid inhomogeneity and discontinuity across the fluid film thickness is incorporated, the shear stresses at the contact‐fluid interfaces are reduced and this reduction can be significant. This reduction may strongly depend on the value of the dimensionless discontinuity parameter Δ/D of the fluid across the fluid film thickness but weakly depend on the number n of the fluid molecules across the fluid film thickness.

Practical implications

An important and very useful research for the academic researcher and the engineer who are, respectively, engaged in the study and design of hydrodynamic lubrication on mechanical components especially of very low hydrodynamic lubrication film thickness. It is also important to the subsequent research of molecularly thin film hydrodynamic lubrication.

Originality/value

A new model of molecularly thin film hydrodynamic lubrication in one‐dimensional contacts is originally proposed and described by incorporating the fluid inhomogeneity and discontinuity effects across the fluid film thickness in this lubrication. This new model of molecularly thin film hydrodynamic lubrication is of importance to the theoretical study of molecularly thin film hydrodynamic lubrication.

Details

Industrial Lubrication and Tribology, vol. 58 no. 3
Type: Research Article
ISSN: 0036-8792

Keywords

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