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Article
Publication date: 12 September 2023

Yanyan Shi, Fenglan Huang, Meng Wang and Yongheng Li

To solve the problem of low sensitivity of traditional capacitive proximity sensor, this paper aims to propose a novel capacitive sensor for detection of an approaching conductor.

Abstract

Purpose

To solve the problem of low sensitivity of traditional capacitive proximity sensor, this paper aims to propose a novel capacitive sensor for detection of an approaching conductor.

Design/methodology/approach

Five capacitive proximity sensors with different structures are designed and the performance is compared with the traditional capacitive sensor. The impacts of geometrical parameters on the performance of the proposed capacitive sensor are studied. Furthermore, the sensitivity of the proposed capacitive sensor to an approaching conductor with different sizes is discussed. Also, how the designed capacitive sensor is sensitive to the lateral placement of the approaching object is analyzed.

Findings

Several capacitive proximity sensor structures have been designed and analyzed. It is found that the capacitive sensor with the top small ring-bottom large ring structure shows stronger electric field distribution around the top electrode and higher sensitivity to the approaching conductor than other sensors. Through further analysis of the proposed sensor, the results demonstrate that proposed capacitive sensor is effective for proximity object detection.

Originality/value

This paper proposes a novel capacitive proximity sensor with top small ring-bottom large ring structure. Compared with the traditional capacitive sensor, the proposed capacitive sensor is more sensitive to the approaching object. This would be helpful for the accurate detection of the approaching object. Also, the top and bottom electrodes are much smaller.

Details

Sensor Review, vol. 43 no. 5/6
Type: Research Article
ISSN: 0260-2288

Keywords

Article
Publication date: 2 July 2018

Samuel Zuk, Alena Pietrikova and Igor Vehec

The purpose of this paper is to analyse the possibilities of mechanical switch replacement by capacitive film touch sensor in applications requiring high reliability and short…

Abstract

Purpose

The purpose of this paper is to analyse the possibilities of mechanical switch replacement by capacitive film touch sensor in applications requiring high reliability and short response time. Advantage of replacing mechanical switch by capacitive touch sensor is no mechanical wear and possible implementation of sensor in application where the switch could not be used or where the flexibility of the sensor substrate is required. The aim of this work is to develop a capacitive touch sensor with the advantage of maximum mechanical resistance, short response time and high sensitivity.

Design/methodology/approach

Based on various possible sensors layouts, the authors realized 18 different (14 self-capacitance and four mutual capacitance) topologies of capacitive sensor for touch applications. Three different technologies – PCB, LTCC and polymer technology – were used to characterize sensor’s behaviour. For precise characterization of different layouts realized on various substrates, the authors used integrated circuit FDC2214 capacitance-to-digital converter.

Findings

Sensing range of the capacitive touch (proximity) sensor is affected by the per cent of area covered by the sensor, and it does not depend on topology of sensor. The highest sensing range offers PCB technology. Flexible substrates can be used as proper substituent to rigid PCB.

Originality/value

The novelty of this work lies in finding the touch capacitive sensors that allow shorter switching times compared to standard mechanical switches.

Details

Microelectronics International, vol. 35 no. 3
Type: Research Article
ISSN: 1356-5362

Keywords

Article
Publication date: 15 April 2020

Guanzheng Wu, Siming Li, Jiayu Hu, Manchen Dong, Ke Dong, Xiuliang Hou and Xueliang Xiao

This paper aims to study the working principle of the capacitive pressure sensor and explore the distribution of pressure acting on the surface of the capacitor. Herein, a kind of…

Abstract

Purpose

This paper aims to study the working principle of the capacitive pressure sensor and explore the distribution of pressure acting on the surface of the capacitor. Herein, a kind of high sensitivity capacitive pressure sensor was prepared by overlaying carbon fibers (CFs) on the surfaces of the thermoplastic elastomer (TPE), the TPE with high elasticity is a dielectric elastomer for the sensor and the CFs with excellent electrical conductivity were designed as the conductor.

Design/methodology/approach

Due to the excellent mechanical properties and electrical conductivity of CFs, it was designed as the conductor layer for the TPE/CFs capacitive pressure sensor via laminating CFs on the surfaces of the columnar TPE. Then, a ‘#' type structure of the capacitive pressure sensor was designed and fabricated.

Findings

The ‘#' type of capacitive pressure sensor of TPE/CFs composite was obtained in high sensitivity with a gauge factor of 2.77. Furthermore, the change of gauge factor values of the sensor under 10 per cent of applied strains was repeated for 1,000 cycles, indicating its outstanding sensing stability. Moreover, the ‘#' type capacitive pressure sensor of TPE/CFs was consisted of several capacitor arrays via laminating CFs, which could detect the distribution of pressure.

Research limitations/implications

The TPE/CFs capacitive pressure sensor was easily fabricated with high sensitivity and quick responsiveness, which is desirably applied in wearable electronics, robots, medical devices, etc.

Originality/value

The outcome of this study will help to fabricate capacitive pressure sensors with high sensitivity and outstanding sensing stability.

Details

Pigment & Resin Technology, vol. 50 no. 5
Type: Research Article
ISSN: 0369-9420

Keywords

Article
Publication date: 26 January 2010

Xiaohui Hu and Wuqiang Yang

The purpose of this paper is to present the sensing mechanism, design issues, performance evaluation and applications for planar capacitive sensors. In the context of…

4340

Abstract

Purpose

The purpose of this paper is to present the sensing mechanism, design issues, performance evaluation and applications for planar capacitive sensors. In the context of characterisation and imaging of a dielectric material under test (MUT), a systematic study of sensor modelling, features and design issues is needed. In addition, the influencing factors on sensitivity distribution, and the effect of conductivity on sensor performance need to be further studied for planar capacitive sensors.

Design/methodology/approach

While analytical methods can provide accurate solutions to sensors of simple geometries, numerical modelling is preferred to obtain sensor response to different design parameters and properties of MUT, and to derive the sensitivity distributions of various electrode designs. Several important parameters have been used to evaluate the response of the sensors in different sensing modes. The designs of different planar capacitive sensor arrays are presented and experimentally evaluated.

Findings

The response features and design guidelines for planar capacitive sensors in different sensing modes have been summarised, showing that the sensor in the transmission mode or the single‐electrode mode is suitable for material characterisation and imaging, while the sensor in the shunt mode is suitable for proximity/displacement measurement. The sensitivity distribution of the sensor depends largely on the geometry of the electrodes. Conductivity causes positive changes for the sensor in the transmission and single‐electrode mode, but negative changes for the sensor in the shunt mode. Experimental results confirm that sensing depths of the sensor arrays and the influence of buried conductor on capacitance measurements are in agreement with simulations.

Research limitations/implications

Experimental verification is needed when a sensor is designed.

Originality/value

This paper provides a comprehensive study for planar capacitive sensors in terms of sensor design, evaluation and applications.

Details

Sensor Review, vol. 30 no. 1
Type: Research Article
ISSN: 0260-2288

Keywords

Article
Publication date: 8 January 2018

Wenqing Kan, Ying Huang, Xiao Zeng, Xiaohui Guo and Ping Liu

The purpose of this paper is to present a dual-mode proximity sensor composed of inductive and capacitive sensing modes, which can help the robot distinguish different objects and…

617

Abstract

Purpose

The purpose of this paper is to present a dual-mode proximity sensor composed of inductive and capacitive sensing modes, which can help the robot distinguish different objects and obtain distance information at the same time. A systematic study of sensor response to various objects and the function of cooperation sensing is needed. Furthermore, the application in the field of robotic area needs to be discussed.

Design/methodology/approach

Numerical modeling of each sensing modes and simulations based on finite element analysis method has been carried out to verify the designed dual-mode sensor. A number of objects composed of different materials are used to research the cooperation perception and proximity sensing functions. In addition, the proposed sensor is used on the palm of a mechanical hand as application experiment.

Findings

The characteristics of the sensor are summarized as follows: the sensing range of inductive mode is 0-5.6 mm for detecting a copper block and the perceive range of capacitive mode is 0-5.1 mm for detecting a plastic block. The collaborative perceive tests validated that the non-ferromagnetism metals can be distinguished by inductive mode. Correspondingly, ferromagnetism metals and dielectric objects are differentiated by capacitive mode. Application experiments results reveal that both plastic bottle and steel bottle could be detected and differentiated. The experimental results are in agreement with those of simulations.

Originality value

This paper provides a study of dual-mode proximity sensor in terms of design, experiments and application.

Details

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

Keywords

Article
Publication date: 2 August 2011

Marina Santo Zarnik, Darko Belavič and Srečko Maček

The purpose of this paper is to consider a capacitive pressure sensor fabricated using low‐temperature cofired ceramic (LTCC) materials and technology as a candidate for an…

Abstract

Purpose

The purpose of this paper is to consider a capacitive pressure sensor fabricated using low‐temperature cofired ceramic (LTCC) materials and technology as a candidate for an energy‐autonomous sensor application. Designing the 3D capacitive sensor structure, with the cofired thick‐film electrodes inside the narrow air gap in the LTCC substrate, was a challenging task, particularly due to the presence of the parasitic elements influencing the sensor's characteristics.

Design/methodology/approach

In this work, different design variants for the thick‐film electrodes of the capacitive sensing structure were studied and compared. The test sensors were designed for the pressure range 0‐10 kPa and manufactured with readout electronics based on a capacitance‐to‐digital conversion.

Findings

The typical sensitivity obtained was 4 fF/kPa, and the temperature coefficient of the sensitivity was 0.03%/°C. The design variant with the guard‐ring electrode showed the best rms resolution of 50 Pa. One drawback of the application could be the sensitivity to atmospheric humidity and the influence of the different media.

Originality/value

This paper focuses on the design of a capacitive gas‐pressure sensor in a 3D LTCC structure. The present study provides a good basis for further optimisation of the design of the cofired electrodes in the capacitive sensing structure.

Details

Microelectronics International, vol. 28 no. 3
Type: Research Article
ISSN: 1356-5362

Keywords

Article
Publication date: 1 January 2008

Ming‐Sze Tong, Tae‐Gyu Chang and Ronan Sauleau

To perform studies and comparisons on the electromagnetic band‐gap (EBG) structures, which are constructed by using a combination of inductive and capacitive elements printed on…

Abstract

Purpose

To perform studies and comparisons on the electromagnetic band‐gap (EBG) structures, which are constructed by using a combination of inductive and capacitive elements printed on guided‐wave transmission lines, and by applying a chirping‐and‐tapering technique.

Design/methodology/approach

An in‐house solver based on finite‐difference time‐domain (FDTD) method is adopted for analysis. Conventionally, EBG characteristics are formed by a series of perforations, considered as capacitive elements, on the ground plane(s). To enhance the performance, an additional inductive element is implemented, which is realized by narrowing the strip over the respective perforated regions. For further enhancement, a chirping‐and‐tapering technique is applied on the combined EBG structures for comparisons.

Findings

Through scattering parameter analysis, it was found that the EBG structures using combined inductive and capacitive elements exhibit a band‐gap behavior superior to the ones built with only inductive or capacitive elements. In another set of comparisons, the modified EBG structures combined with a chirping‐and‐tapering technique resulted in further widening of band‐gap, as well as lower side‐lobes and a smoother transition towards the band‐gap region.

Research limitations/implications

Research was mainly limited to studying solely the EBG structures printed on guided‐wave transmission lines.

Practical implications

The proposed EBG structures may be applied into various areas, such as microelectronics and mobile communications for harmonic suppressions, and into other practical electronic circuit structures.

Originality/value

The ideas on applying combined inductive and capacitive elements on various guided‐wave transmission lines to induce EBG characteristics, together with applications of a chirping‐and‐tapering technique on the combined EBG structures give rise to the research originality.

Details

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

Keywords

Article
Publication date: 26 August 2014

Damir Krklješ, Dragana Vasiljević and Goran Stojanović

This paper aims to present a prototype of a capacitive angular-position sensor which exploits advantages of flexible/printed electronics. The novelty of the sensor is that the…

Abstract

Purpose

This paper aims to present a prototype of a capacitive angular-position sensor which exploits advantages of flexible/printed electronics. The novelty of the sensor is that the capacitor structure is placed at the circumference of the rotor and stator, that it posses two channels (capacitor structures) electrically shifted for p/4 and that the rotor is common for both channels. The electrodes of the sensing capacitor are digitated, providing a triangular transfer function.

Design/methodology/approach

This sensor prototype consists of two flexible inkjet-printed silver electrodes forming a cylindrical capacitor structure. One of them is wrapped around the stator and another is wrapped around the rotor part of a simple mechanical platform used to precisely adjust the angular displacement.

Findings

The capacitance as a function of angular position was measured using an inductance capacitance impedance (LCZ) Meter, and results are presented for a full-turn measurement range. The experimental results are compared with analytical ones and very good agreement has been achieved.

Originality/value

The proposed capacitive sensor structure can be used as an absolute or an incremental encoder with different resolutions, and it can be applied in automotive industry or robotics.

Details

Sensor Review, vol. 34 no. 4
Type: Research Article
ISSN: 0260-2288

Keywords

Article
Publication date: 4 January 2008

Jérôme Lucas, Stéphane Holé and Christophe Bâtis

The purpose of this paper is to introduce a rapid method for calculating capacitive sensor signal variations for any small permittivity or electrode modifications at any position…

1170

Abstract

Purpose

The purpose of this paper is to introduce a rapid method for calculating capacitive sensor signal variations for any small permittivity or electrode modifications at any position in space.

Design/methodology/approach

When a capacitive sensor is probing its surrounding, the modification of the permittivity, the displacement or the deformation of one or more electrodes induce a signal variation which depends on the position of the modification. Seeing that modification as a small perturbation and using Gauss identity, it is possible to find integral expressions of the sensor sensitivity map.

Findings

Capacitive sensor sensitivity map expressions depend only on the perturbation to measure, on the electric field before the perturbation, and on a sensitivity field which is the electric field produced by the sensor when the measuring electrode is held to 1 V while the others, except the floating ones, are grounded. The sensitivity field is a kind of Green's function for the capacitive sensor. The knowledge of the electric and sensitivity fields makes it possible to obtain the whole sensor sensitivity map at once without requiring time consuming parametric calculations.

Originality/value

The sensitivity field calculation provides a simple and direct view of the capacitive sensor capabilities. That should improve capacitive sensor design.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 27 no. 1
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 6 July 2020

Igor S. Nadezhdin and Aleksey G. Goryunov

Differential pressure is an important technological parameter, one urgent task of which is control and measurement. To date, the lion’s share of research in this area has focused…

Abstract

Purpose

Differential pressure is an important technological parameter, one urgent task of which is control and measurement. To date, the lion’s share of research in this area has focused on the development and improvement of differential pressure sensors. The purpose of this paper is to develop a smart differential pressure sensor with improved operational and metrological characteristics.

Design/methodology/approach

The operating principle of the developed pressure sensor is based on the capacitive measurement principle. The measuring unit of the developed pressure sensor is based on a differential capacitive sensitive element. Programmable system-on-chip (PSoC) technology has been used to develop the electronics unit.

Findings

The use of a differential capacitive sensitive element allows the unit to compensate for the influence of interference (for example, temperature) on the measurement result. With the use of PSoC technology, it is also possible to increase the noise immunity of the developed smart differential pressure sensor and provide an unparalleled combination of flexibility and integration of analog and digital functionality.

Originality/value

The use of PSoC technology in the developed smart differential pressure sensor has many indisputable advantages, as the size of the entire circuit can be minimized. As a result, the circuit has improved noise immunity. Accordingly, the procedure for debugging and changing the software of the electronics unit is simplified. These features make development and manufacturing cost effective.

Details

Sensor Review, vol. 40 no. 5
Type: Research Article
ISSN: 0260-2288

Keywords

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