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Article
Publication date: 7 July 2020

Ahamed Saleel C., Asif Afzal, Irfan Anjum Badruddin, T.M. Yunus Khan, Sarfaraz Kamangar, Mostafa Abdelmohimen, Manzoore Elahi M. Soudagar and H. Fayaz

The characteristics of fluid motions in micro-channel are strong fluid-wall surface interactions, high surface to volume ratio, extremely low Reynolds number laminar flow…

Abstract

Purpose

The characteristics of fluid motions in micro-channel are strong fluid-wall surface interactions, high surface to volume ratio, extremely low Reynolds number laminar flow, surface roughness and wall surface or zeta potential. Due to zeta potential, an electrical double layer (EDL) is formed in the vicinity of the wall surface, namely, the stern layer (layer of immobile ions) and diffuse layer (layer of mobile ions). Hence, its competent designs demand more efficient micro-scale mixing mechanisms. This paper aims to therefore carry out numerical investigations of electro osmotic flow and mixing in a constricted microchannel by modifying the existing immersed boundary method.

Design/methodology/approach

The numerical solution of electro-osmotic flow is obtained by linking Navier–Stokes equation with Poisson and Nernst–Planck equation for electric field and transportation of ion, respectively. Fluids with different concentrations enter the microchannel and its mixing along its way is simulated by solving the governing equation specified for the concentration field. Both the electro-osmotic effects and channel constriction constitute a hybrid mixing technique, a combination of passive and active methods. In microchannels, the chief factors affecting the mixing efficiency were studied efficiently from results obtained numerically.

Findings

The results indicate that the mixing efficiency is influenced with a change in zeta potential (ζ), number of triangular obstacles, EDL thickness (λ). Mixing efficiency decreases with an increment in external electric field strength (Ex), Peclet number (Pe) and Reynolds number (Re). Mixing efficiency is increased from 28.2 to 50.2% with an increase in the number of triangular obstacles from 1 to 5. As the value of Re and Pe is decreased, the overall percentage increase in the mixing efficiency is 56.4% for the case of a mixing micro-channel constricted with five triangular obstacles. It is also vivid that as the EDL overlaps in the micro-channel, the mixing efficiency is 52.7% for the given zeta potential, Re and Pe values. The findings of this study may be useful in biomedical, biotechnological, drug delivery applications, cooling of microchips and deoxyribonucleic acid hybridization.

Originality/value

The process of mixing in microchannels is widely studied due to its application in various microfluidic devices like micro electromechanical systems and lab-on-a-chip devices. Hence, its competent designs demand more efficient micro-scale mixing mechanisms. The present study carries out numerical investigations by modifying the existing immersed boundary method, on pressure-driven electro osmotic flow and mixing in a constricted microchannel using the varied number of triangular obstacles by using a modified immersed boundary method. In microchannels, the theory of EDL combined with pressure-driven flow elucidates the electro-osmotic flow.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 31 no. 3
Type: Research Article
ISSN: 0961-5539

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Article
Publication date: 28 July 2021

Sudarsana Jena and Ankur Gupta

Considering its vast utility in industries, this paper aims to present a detailed review on fundamentals, classification and progresses in pressure sensors, along with its…

Abstract

Purpose

Considering its vast utility in industries, this paper aims to present a detailed review on fundamentals, classification and progresses in pressure sensors, along with its wide area of applications, its design aspects and challenges, to provide state-of-the-art gist to the researchers of the similar domain at one place.

Design/methodology/approach

Swiftly emerging research prospects in the micro-electro-mechanical system (MEMS) enable to build complex and sophisticated micro-structures on a substrate containing moving masses, cantilevers, flexures, levers, linkages, dampers, gears, detectors, actuators and many more on a single chip. One of the MEMS initial products that emerged into the micro-system technology is MEMS pressure sensor. Because of their high performance, low cost and compact in size, these sensors are extensively being adopted in numerous applications, namely, aerospace, automobile and bio-medical domain, etc. These application requirements drive and impose tremendous conditions on sensor design to overcome the tedious design and fabrication procedure before its reality. MEMS-based pressure sensors enable a wide range of pressure measurement as per the application requirements.

Findings

The paper provides a detailed review on fundamentals, classification and progresses in pressure sensors, along with its wide area of applications, its design aspects and challenges, to provide state of the art gist to the researchers of the similar domain at one place.

Originality/value

The present paper discusses the basics of MEMS pressure sensors, their working principles, different design aspects, classification, type of sensing diaphragm used and illustration of various transduction mechanisms. Moreover, this paper presents a comprehensive review on present trend of research on MEMS-based pressure sensors, its applications and the research gap observed till date along with the scope for future work, which has not been discussed in earlier reviews.

Details

Sensor Review, vol. 41 no. 3
Type: Research Article
ISSN: 0260-2288

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Article
Publication date: 5 March 2018

Pandiyan P., Uma G. and Umapathy M.

The purpose of this paper is to design an out-of-plane micro electro-thermal-compliant actuator based logic gates which work analogously to complementary metal oxide…

Abstract

Purpose

The purpose of this paper is to design an out-of-plane micro electro-thermal-compliant actuator based logic gates which work analogously to complementary metal oxide semiconductor (CMOS) based logic gates. The proposed logic gates used a single-bit mechanical micro ETC actuator per logic instead of using 6-14 individual transistors as in CMOS.

Design/methodology/approach

A complete analytical modelling is performed on a single ETC vertical actuator, and a relation between the applied voltage and the out-of-plane deflection is derived. Its coupled electro-thermo-mechanical analysis is carried out using micro electro mechanical system (MEMS) CAD tool CoventorWare to illustrate its performance.

Findings

This paper reports analytical and numerical simulation of basic MEMS ETC actuator-based logic gates. The proposed logic gate operates on 5 V, which suits well with conventional CMOS logic, which in turn reduces the power consumption of the device.

Originality/value

The proposed logic gates uses a single-bit MEMS ETC actuator per logic instead of using more transistors as in CMOS. The unique feature of this proposed logic gates is that the basic mechanical ETC actuator is customized in its structure to function as specific logic gates depending upon the given inputs.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 37 no. 2
Type: Research Article
ISSN: 0332-1649

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Article
Publication date: 1 April 2014

Yong-long Tang, Zhi-jing Zhang, Xin Ye and Xiao-feng Zhang

– The purpose of this paper is to propose a novel method of coaxial optical precision alignment based on surface roughness and reflectiveness matching.

Abstract

Purpose

The purpose of this paper is to propose a novel method of coaxial optical precision alignment based on surface roughness and reflectiveness matching.

Design/methodology/approach

The micro-assembly experiment system set-up was constructed according to the principle of the coaxial optical alignment. The coaxial optical alignment error is theoretically analyzed and calculated. When the prism orthogonal alignment mechanism produces the error of 0.001°, the theoretical deviation was less than 0.87 μm and the actual experimental micro-assembly platform assembly accuracy exceeded 3 μm. A peg-in-hole precise assembly of punching pin micro-assembly experiment was done in order to validate feasibility of this method.

Findings

The results indicate that coaxial optical precision alignment could be used for the assembly of complex micro-heterogeneous system which is integrated by similar devices, such as 3D complex micro-structures, silicon micro-electro-mechanical system (MEMS) devices and non-silicon MEMS devices with flat structure.

Originality/value

The paper provides certain methodological guidelines for MEMS for high precision automatic assembly of complex 3D micro-structures.

Details

Assembly Automation, vol. 34 no. 2
Type: Research Article
ISSN: 0144-5154

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Article
Publication date: 8 January 2018

Milos Milovancevic and Edvard Tijan

The purpose of this research paper is to develop and analyze micro-electro-mechanical systems sensor for vibration monitoring of pumping aggregate.

Abstract

Purpose

The purpose of this research paper is to develop and analyze micro-electro-mechanical systems sensor for vibration monitoring of pumping aggregate.

Design/methodology/approach

The system is based on smart sensor and smart mobile phone.

Findings

The numerous measurements on a wide range of turbo aggregates were performed to establish the operating condition of pumping aggregates.

Originality/value

Afterwards, the influence of vibration at different positions on the output vibration of the pumping aggregate was analyzed by adaptive neuro fuzzy inference system method.

Details

Sensor Review, vol. 38 no. 2
Type: Research Article
ISSN: 0260-2288

Keywords

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Article
Publication date: 5 January 2015

Norihan Abdul Hamid, J. Yunas, B. Yeop Majlis, A.A. Hamzah and B. Bais

The purpose of this paper is to discuss the fabrication technology and test of thermo-pneumatic actuator utilizing Si3N4-polyimide thin film membrane. Thin film polyimide…

Abstract

Purpose

The purpose of this paper is to discuss the fabrication technology and test of thermo-pneumatic actuator utilizing Si3N4-polyimide thin film membrane. Thin film polyimide membrane capped with Si3N4 thin layer is used as actuator membrane which is able to deform through thermal forces inside an isolated chamber. The fabricated membrane will be suitable for thermo-pneumatic-based membrane actuation for lab-on-chip application.

Design/methodology/approach

The actuator device consisting of a micro-heater, a Si-based micro-chamber and a heat-sensitive square-shaped membrane is fabricated using surface and bulk-micromachining process, with an additional adhesive bonding process. The polyimide membrane is capped with a thin silicon nitride layer that is fabricated by using etch stop technique and spin coating.

Findings

The deformation property of the membrane depend on the volumetric expansion of air particles in the heat chamber as a result of temperature increase generated from the micro-heater inside the chamber. Preliminary testing showed that the fabricated micro-heater has the capability to generate heat in the chamber with a temperature increase of 18.8 °C/min. Analysis on membrane deflection against temperature increase showed that heat-sensitive thin polyimide membrane can perform the deflection up to 65 μm for a temperature increase of 57°C.

Originality/value

The dual layer polyimide capped with Si3N4 was used as the membrane material. The nitride layer allowed the polyimide membrane for working at extreme heat condition. The process technique is simple implementing standard micro-electro-mechanical systems process.

Details

Microelectronics International, vol. 32 no. 1
Type: Research Article
ISSN: 1356-5362

Keywords

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Article
Publication date: 1 January 2006

Wenchao Tian, Jianyuan Jia, Guiming Chen and Guangyan Chen

The “Snap back” problem of the micro‐cantilever remains one of the dominant failure mechanisms in the Micro Electromechanical System (MEMS). By analyzing the Hamaker micro

Abstract

The “Snap back” problem of the micro‐cantilever remains one of the dominant failure mechanisms in the Micro Electromechanical System (MEMS). By analyzing the Hamaker micro continuum medium and solid physics principle, the consistency model of Wigner‐Seitz (W‐S) continuum medium is presented. The gap revision coefficients of the body with the face‐centered cubic structure are derived, which include the attractive force and the repulsive one. The adhesion model of the 500 µ m X 1 µ m silicon micro‐cantilever coated by Au is established. The micro‐cantilever static relationship between the elastic force and the adhesion force is discussed. The reason of the microcantilever “snap back” problem, an instable balanced point, is discovered. Increasing the rigidity of the micro‐cantilever, a method to avoid the micro‐cantilever “snap back” to happen, is put forward, which improves MEMS structure design and enhances MEMS reliability.

Details

Multidiscipline Modeling in Materials and Structures, vol. 2 no. 1
Type: Research Article
ISSN: 1573-6105

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Article
Publication date: 10 May 2011

Dejan V. Tošić and Marija F. Hribšek

The purpose of this paper is to model multilayer structure surface acoustic wave (SAW) sensors, incorporated in CMOS or microelectromechanical system integrated…

Abstract

Purpose

The purpose of this paper is to model multilayer structure surface acoustic wave (SAW) sensors, incorporated in CMOS or microelectromechanical system integrated circuits, and to derive the corresponding wave velocity as an analytic expression in terms of the layers‘ thickness and density, which is suitable for analysis and design.

Design/methodology/approach

The method is based on an electromechanical equivalent model of multilayer structure SAW sensors. A multilayered SAW device is represented by a two‐port electrical equivalent circuit consisting of three parts: input transducer, output transducer, and between them the delay line, which is the sensing part. The sensing part is modelled as a mechanical two‐port network. The wave velocity is calculated using analogy between the mechanical and electrical quantities and the fact that the wave motion of the SAW extends below the surface to a depth of about one wavelength.

Findings

The presented model predicts very efficiently and accurately the velocity of SAW sensors with multilayer substrates in the case where the thicknesses of upper layers are much smaller than the signal wavelength. The velocity can be calculated from the formula, so that elaborate numerical computations involving partial differential equations are avoided.

Research limitations/implications

The model and the velocity calculation can be applied only to acoustically thin upper and middle layers where acoustically thin means that a layer is sufficiently thin and rigid (large shear modulus). The presented results provide a starting‐point for further research in the analysis and design of sensors fabricated using AlGaN, GaN, AlN/diamond.

Practical implications

Since the majority of SAW sensors is designed with acoustically thin layers, the proposed model and calculation can be of interest for many practical material combinations. The presented model and calculation can be used in most cases of the optimal sensor design with respect to the sensor sensitivity or required area on the sensor chip.

Originality/value

The paper presents a new original model of multilayer structure SAW sensors and a new method of SAW velocity calculation. The method gives good results, with much simpler calculations than in the wave equation method, in cases where certain layers are acoustically thin.

Details

Microelectronics International, vol. 28 no. 2
Type: Research Article
ISSN: 1356-5362

Keywords

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Article
Publication date: 5 January 2015

Jae B. Kwak and Seungbae Park

The purpose of this paper was to study the combined effect of hygro and thermo-mechanical behavior on a plastic encapsulated micro-electro-mechanical systems (MEMS…

Abstract

Purpose

The purpose of this paper was to study the combined effect of hygro and thermo-mechanical behavior on a plastic encapsulated micro-electro-mechanical systems (MEMS) package during the reflow process after exposed to a humid environment for a prolonged time. Plastic encapsulated electronic packages absorb moisture when they are subjected to humid ambient conditions.

Design/methodology/approach

Thus, a comprehensive stress model is established for a three-axis accelerometer MEMS package, with detailed considerations of fundamentals of mechanics such as heat transfer, moisture diffusion and hygro-thermo-mechanical stress. In this study, the mold compound is considered to be the most critical plastic material in MEMS package. Other plastic components of thin film materials can be disregarded due to their small sizes such as die attach and Bismaleimide Triazine (BT) core, even though they are also susceptible to moisture. Thus, only the moisture-induced properties of mold compound were obtained from the proposed experiments. From the desorption measurement after preconditioning at 85°C/85 per cent relative humidity (RH), the saturated moisture content and diffusivity were obtained by curve fitting the data to Fick’s equation. In addition, a new experimental setup was devised using the digital image correlation system together with a precision weight scale to obtain the coefficient of hygroscopic swelling (CHS) at different temperatures.

Findings

The experimental results show that the diffusion coefficient of mold compound material follows Arrhenius equation well. Also, it is shown that the CHS of mold compound increases as temperature increases. Experimentally obtained moisture properties were then used to analyze the combined behavior (thermo-hygro-mechanical) of fully saturated MEMS package during the reflow process using a finite element analysis (FEA) with the classical analogy method. Finally, the warpage and stresses inside the MEMS package were analyzed to compare the effects of hygroscopic, thermal and hygro-thermo-mechancal behaviors.

Originality/value

In this study, unlike the other researches, the moisture effects are investigated specifically for MEMS package which is relatively smaller in scale than conventional electronic packages. Also, as a conjugated situation, MEMS package experiences both humid and temperature during the moisture resistance test. Thus, major objective of this study is to verify stress state inside MEMS package during the reflow process which follows the preconditioning at 85°C/85 per cent RH. To quantify the stresses in the package, accurate information of material properties is experimentally obtained and used to improve modeling accuracy.

Details

Microelectronics International, vol. 32 no. 1
Type: Research Article
ISSN: 1356-5362

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Article
Publication date: 1 December 2004

Vincent Henneken, Marcel Tichem and Bernhard Karpuschewski

An alternative way of performing micro‐assembly tasks is by means of product‐internal assembly functions. After a coarse alignment step, the parts are fine positioned…

Abstract

An alternative way of performing micro‐assembly tasks is by means of product‐internal assembly functions. After a coarse alignment step, the parts are fine positioned relative to each other by functionality that is integrated with the product. This functionality includes part actuation, position sensing and part freezing. They replace expensive machinery and delicate manual labour, and are aimed to result in lower total production costs. Micro electro mechanical system (MEMS) technology has important benefits to be used as supporting technology, because it allows for cost reduction (batch production), and structures can be made with small dimensions and high accuracy. The objective of this paper is to develop a reliable and reproducible interconnection technology using MEMS‐based product‐internal assembly functions, by which packaging cost is reduced and yield is improved. The considered case is the packaging of optical fibre to chip couplings.

Details

Assembly Automation, vol. 24 no. 4
Type: Research Article
ISSN: 0144-5154

Keywords

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