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Article
Publication date: 1 December 2005

A. Arshak, K. Arshak, G. Lyons, D. Waldron, D. Morris, O. Korostynska and E. Jafer

Telemetry capsules have existed since the 1950s and were used to measure temperature, pH or pressure inside the gastrointestinal (GI) tract. It was hoped that these…

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1422

Abstract

Purpose

Telemetry capsules have existed since the 1950s and were used to measure temperature, pH or pressure inside the gastrointestinal (GI) tract. It was hoped that these capsules would replace invasive techniques in the diagnosis of function disorders in the GI tract. However, problems such as signal loss and uncertainty of the pills position limited their use in a clinical setting. In this paper, a review of the capabilities of microelectromechanical systems (MEMS) for the fabrication of a wireless pressure sensor microsystem is presented.

Design/methodology/approach

The circuit requirements and methods of data transfer are examined. The available fabrication methods for MEMS sensors are also discussed and examples of wireless sensors are given. Finally, the drawbacks of using this technology are examined.

Findings

MEMS for use in wireless monitoring of pressure in the GI tract have been investigated. It has been shown that capacitive pressure sensors are particularly suitable for this purpose. Sensors fabricated for wireless continuous monitoring of pressure have been reviewed. Great progress, especially using surface micromachining, has been made in recent years. However, despite these advances, some challenges remain.

Originality/value

Provides a review of the capabilities of MEMS.

Details

Sensor Review, vol. 25 no. 4
Type: Research Article
ISSN: 0260-2288

Keywords

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Article
Publication date: 1 June 1996

R.A. Lawes

Reviews some of the more important technologies used for fabricating microcomponents and systems – bulk silicon micromachining, surface micromachining and LIGA, a process…

Abstract

Reviews some of the more important technologies used for fabricating microcomponents and systems – bulk silicon micromachining, surface micromachining and LIGA, a process for forming deep microstructures by lithography, electroforming and moulding. Discusses the relative merits of using synchroton, electron beam and excimer laser irradiation. Gives a comb actuator and an electrostatic motor as examples of micromachined components.

Details

Sensor Review, vol. 16 no. 2
Type: Research Article
ISSN: 0260-2288

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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: 14 September 2010

Bian Tian, Yulong Zhao and Zhuangde Jiang

The purpose of this paper is to investigate the disadvantages of traditional sensors and establish a new structure for pressure measurement.

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1183

Abstract

Purpose

The purpose of this paper is to investigate the disadvantages of traditional sensors and establish a new structure for pressure measurement.

Design/methodology/approach

A kind of novel piezoresistive micro‐pressure sensor with a cross‐beam membrane (CBM) structure is designed based on the silicon substrate. Through analyzing the stress distribution of the new structure by finite element method, the model of structure is established and compared with traditional structures. The fabrication is operated on silicon wafer, which applies the technology of anisotropy chemical etching and inductively coupled plasma.

Findings

Compared to the traditional C‐ and E‐type structures, this new CBM structure has the advantages of low nonlinearity and high sensitivities by the cross‐beam on the membrane, which cause the stress is more concentrated in sensitive area and the deflections that relate to the linearity are decreased.

Originality/value

The paper provides the first empirical reports on the new piezoresistive structure for the pressure measurement by fabricating a cross‐beam on the membrane and resolving the conflict of nonlinearity and sensitivity of the piezoresistive sensors.

Details

Sensor Review, vol. 30 no. 4
Type: Research Article
ISSN: 0260-2288

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Article
Publication date: 3 April 2007

Gino Rinaldi, Muthukumaran Packirisamy and Ion Stiharu

This paper seeks to establish an analytical reference model in order to optimize the frequency response of MEMS cantilever structures using cutouts.

Abstract

Purpose

This paper seeks to establish an analytical reference model in order to optimize the frequency response of MEMS cantilever structures using cutouts.

Design/methodology/approach

Presented in this work is a method to tune the frequency response of MEMS cantilevers by using single cutouts of various sizes. From an interpretation of the analytical results, mass and stiffness domains are defined as a function of the cutout position on the cantilever. In this regard, the elastic properties of the MEMS cantilever can be trimmed through mechanical tuning by a single cutout incorporated into the device geometry. The Rayleigh‐Ritz energy method is used for the modeling. Analytical results are compared with FEM and experimental results.

Findings

The eigenvalues are dependent on the position and size of the cutout. Hence, the frequency response of the cantilever can be tuned and optimized through this approach.

Research limitations/implications

MEMS microsystems are sensitive to microfabrication limitations especially at the boundary support of suspended structures such as microcantilevers.

Practical implications

MEMS cantilevers are resistant to low level vibrations due to their low inertia and the elastic properties of the silicon material. For sensor applications these qualities are highly regarded and explored. This analysis will contribute to the performance optimization of atomic force microscope (AFM) probes and micromechanical resonators.

Originality/value

A method to tune, with cutouts, the frequency response of microcantilevers is proposed. The data can provide insight into the performance optimization of micromechanical resonators through mass reduction. For industrial applications requiring optimized responses the cutouts can be incorporated into microcantilevers through focused ion beam (FIB) machining or laser drilling, for example.

Details

Sensor Review, vol. 27 no. 2
Type: Research Article
ISSN: 0260-2288

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Article
Publication date: 1 June 1996

F. Yalcinkaya and E.T. Powner

Reviews intelligent structures through surface‐ and bulkmicromachining. Examines the merits of these techniques and their past, present and future applications to…

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257

Abstract

Reviews intelligent structures through surface‐ and bulkmicromachining. Examines the merits of these techniques and their past, present and future applications to real‐life problems.

Details

Sensor Review, vol. 16 no. 2
Type: Research Article
ISSN: 0260-2288

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Article
Publication date: 1 July 2004

J.L. Xu, Z.Q. Zhou and X.D. Xu

The molecular dynamics simulation of micro‐Poiseuille flow for liquid argon in nanoscale was performed in non‐dimensional unit system with the control parameters of…

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1749

Abstract

The molecular dynamics simulation of micro‐Poiseuille flow for liquid argon in nanoscale was performed in non‐dimensional unit system with the control parameters of channel size, coupling parameters between solid wall and liquid particles, and the gravity force. The molecular forces are considered not only among the liquid molecules, but also between the solid wall and liquid molecules. The simulation shows that a larger gravity force produces a larger shear rate and a higher velocity distribution. In terms of the gravity force, there are three domain regions each with distinct flow behaviors: free molecule oscillation, coupling and gravity force domain regions. Stronger fluid/wall interactions can sustain a larger coupling region, in which the flow is controlled by the balance of the intermolecular force and the gravity force. Strong surface interaction leads to small slip lengths and the slip lengths are increased slightly with increasing the shear rate. Weak surface interaction results in higher slip lengths and the slip lengths are dramatically decreased with increasing the shear rate. The viscosities are nearly kept constant (Newton flow behavior) if the non‐dimensional shear rate is below 2.0. At higher non‐dimensional shear rate larger than 2.0, the viscosities have a sharp increase with increasing the shear rate, and the non‐Newton flow appears.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 14 no. 5
Type: Research Article
ISSN: 0961-5539

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Article
Publication date: 1 April 2003

T. Lalinsky´, Sˇ. Haščík, Ž. Mozolová, E. Burian, M. Krnáč, M. Tomáška, J. Škriniarová, M. Drzˇík, I. Kosticˇ and L. Matay

A new micromachining technology of mechanically fixed and thermally insulated cantilevers, bridges and islands was developed to be used for design of GaAs heterostructure…

Abstract

A new micromachining technology of mechanically fixed and thermally insulated cantilevers, bridges and islands was developed to be used for design of GaAs heterostructure based microelectromechanical systems (MEMS) devices. Based on the micromachining technology, two different MEMS devices were designed and analyzed. The first one was micromechanical thermal converter (MTC) and the second one was a micromechanical coplanar waveguide (MCPW). The basic electro‐thermal as well as microwave properties of the MEMS devices designed are investigated. The results obtained are also supported by simulation. The advantages of the fixed micromechanical structures in the field of design of new MEMS devices are discussed.

Details

Microelectronics International, vol. 20 no. 1
Type: Research Article
ISSN: 1356-5362

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Article
Publication date: 1 January 2014

Said M.M. Kafumbe

The processing techniques and materials utilized in the fabrication of a two-terminal electrostatically actuated micro-electro-mechanical cantilever-arrayed device used…

Abstract

Purpose

The processing techniques and materials utilized in the fabrication of a two-terminal electrostatically actuated micro-electro-mechanical cantilever-arrayed device used for radio frequency tuning applications are presented in this work. The paper aims to discuss these issues.

Design/methodology/approach

The process, which is based on silicon surface micromachining, uses spin-coated photoresist as the sacrificial layer underneath the electroplated gold structural material and an insulating layer of silicon dioxide, deposited using plasma enhanced chemical vapour deposition (PECVD), to avoid a short circuit between the cantilever and the bottom electrode in a total of six major fabrication steps. These included the PECVD of the silicon dioxide insulating layer, optical lithography to transfer photomask layer patterns, vacuum evaporation to deposit thin films of titanium (Ti) and gold (Au), electroplating of Au, the dry release of the cantilever beam arrays, and finally the wafer dicing to split the different micro devices. These process steps were each sub-detailed to give a total of 14 micro-fabrication processes.

Findings

Scanning electron microscope images taken on the final fabricated device that was dry released using oxygen plasma ashing to avoid stiction showed 12 freely suspended micro-cantilevered beams suspended with an average electrostatic gap of 2.29±0.17 μm above a 4,934±3 Å thick silicon dioxide layer. Preliminary dimensional measurements on the fabricated devices revealed that the cantilevers were at least 52.06±1.93 μm wide with lengths varying from 377.97±0.01 to 1,491.89±0.01 μm and were at least 2.21±0.05 μm thick.

Originality/value

The cantilever beams used in this work were manufactured using electroplated gold, and photoresist was used as a sacrificial layer underneath the beams. Plasma ashing was used to release the beams. The beams were anchored to a central electrode and each beam was designed with varying length.

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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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