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Special Issue "Sensors for MEMS and Microsystems"

A special issue of Sensors (ISSN 1424-8220). This special issue belongs to the section "Physical Sensors".

Deadline for manuscript submissions: closed (31 December 2018)

Special Issue Editor

Guest Editor
Prof. Dr. Dan Zhang

Department of Mechanical Engineering, Lassonde School of Engineering, York University, 4700 Keele Street, Toronto, ON M3J 1P3, Canada
Website | E-Mail
Interests: robotics and mechatronics; high performance parallel robotic machine development; sustainable/green manufacturing systems; micro/nano manipulation and MEMS devices (sensors), micro mobile robots and control of multi-robot cooperation, intelligent servo control system for the MEMS based high-performance micro-robot; web-based remote manipulation; rehabilitation robot and rescue robot

Special Issue Information

Dear Colleagues,

In the modern engineering world, it is rare that anything is purely mechanical or electrical engineering. More often than not, problems faced by engineers require an integration of mechanical and electrical aspects, along with control and software, to develop a viable solution. The domain of mechatronics engineering represents the fusion of these four areas. This special issue has a particular emphasis on sensors used for MEMS and micro-systems, where MEMS devices are designed to operate with a degree of intelligence. It also provides a suitable background for research in advanced mechatronics and MEMS systems as well as its fabrication. The aim of the special issue is to introduce the state-of-the-art technologies in the field of sensors, mechatronics, MEMS devices and micro-systems in order to further summarize and improve the methodologies on the micro-systems and MEMS Devices.

Prof. Dr. Dan Zhang
Guest Editor

Manuscript Submission Information

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Keywords

  • MEMS devices
  • micro-system
  • micro fabrication
  • compliant mechanisms
  • sensors for mechatronics devices
  • sensors for MEMS devices and micro-systems

Published Papers (17 papers)

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Research

Open AccessArticle Design and DOF Analysis of a Novel Compliant Parallel Mechanism for Large Load
Sensors 2019, 19(4), 828; https://doi.org/10.3390/s19040828
Received: 20 December 2018 / Revised: 9 February 2019 / Accepted: 13 February 2019 / Published: 17 February 2019
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Abstract
The degree of freedom (DOF) and motion characteristics of a kind of compliant spherical joint were analyzed based on the screw theory, and a new design scheme for force-inversion of the compliant spherical joint was proposed in this paper. A novel type of [...] Read more.
The degree of freedom (DOF) and motion characteristics of a kind of compliant spherical joint were analyzed based on the screw theory, and a new design scheme for force-inversion of the compliant spherical joint was proposed in this paper. A novel type of six DOF compliant parallel mechanism (CPM) was designed based on this scheme to provide a large load capacity and achieve micrometer-level positioning accuracy. The compliance matrix of the new type of CPM was obtained through matrix transformation and was then decomposed into its generalized eigenvalues. Then, the DOF of the mechanism was numerically analyzed based on the symbolic formulation. The finite element analysis model of the compliant parallel mechanism was established. The static load analysis was used to verify the large load capacity of the mobile platform. By comparing the deformation obtained by the compliance matrix numerical method with the deformation obtained by the finite element method, the correctness of the compliance matrix and the number of the DOF of the CPM was verified. Full article
(This article belongs to the Special Issue Sensors for MEMS and Microsystems)
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Open AccessArticle HEALPix-IA: A Global Registration Algorithm for Initial Alignment
Sensors 2019, 19(2), 427; https://doi.org/10.3390/s19020427
Received: 12 December 2018 / Revised: 16 January 2019 / Accepted: 18 January 2019 / Published: 21 January 2019
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Abstract
Methods of point cloud registration based on ICP algorithm are always limited by convergence rate, which is related to initial guess. A good initial alignment transformation can sharply reduce convergence time and raise efficiency. In this paper, we propose a global registration method [...] Read more.
Methods of point cloud registration based on ICP algorithm are always limited by convergence rate, which is related to initial guess. A good initial alignment transformation can sharply reduce convergence time and raise efficiency. In this paper, we propose a global registration method to estimate the initial alignment transformation based on HEALPix (Hierarchical Equal Area isoLatitude Pixelation of a sphere), an algorithm for spherical projections. We adopt EGI (Extended Gaussian Image) method to map the normals of the point cloud and estimate the transformation with optimized point correspondence. Cross-correlation method is used to search the best alignment results in consideration of the accuracy and robustness of the algorithm. The efficiency and accuracy of the proposed algorithm were verified with created model and real data from various sensors in comparison with similar methods. Full article
(This article belongs to the Special Issue Sensors for MEMS and Microsystems)
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Open AccessArticle Modelling and Design of MEMS Piezoresistive Out-of-Plane Shear and Normal Stress Sensors
Sensors 2018, 18(11), 3737; https://doi.org/10.3390/s18113737
Received: 5 October 2018 / Revised: 27 October 2018 / Accepted: 29 October 2018 / Published: 2 November 2018
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Abstract
In this paper, the design of MEMS piezoresistive out-of-plane shear and normal stress sensor is described. To improve the sensor sensitivity, a methodology by the incorporation of stress concentration regions, namely surface trenches in the proximity of sensing elements was explored in detail. [...] Read more.
In this paper, the design of MEMS piezoresistive out-of-plane shear and normal stress sensor is described. To improve the sensor sensitivity, a methodology by the incorporation of stress concentration regions, namely surface trenches in the proximity of sensing elements was explored in detail. The finite element (FE) model, verified by a five-layer analytical model was developed as a tool to model the performance of the sensor and guide the geometric optimization of the surface trenches. Optimum location and dimensions of the surface trenches have been obtained through a comprehensive FE analysis. The microfabrication and packing scheme was introduced to prototype the sensor with optimum geometric characteristics of surface trenches. Signal output from the prototyped sensor was tested and compared with those from FE simulation. Good agreement has been achieved between the simulation and experimental results. Moreover, the results suggest the incorporation of surface trenches can help improve the sensor sensitivity. More specifically, the sum of signal output from the sensor chip with surface trenches are 4.52, 5.06 and 5.72 times higher compared to flat sensor chip for center sensing area, edge sensing areas 1 and 2, respectively. Full article
(This article belongs to the Special Issue Sensors for MEMS and Microsystems)
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Open AccessArticle A Non-Linear Model of an All-Elastomer, in-Plane, Capacitive, Tactile Sensor Under the Application of Normal Forces
Sensors 2018, 18(11), 3614; https://doi.org/10.3390/s18113614
Received: 20 September 2018 / Revised: 21 October 2018 / Accepted: 22 October 2018 / Published: 24 October 2018
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Abstract
In this work, a large deformation, non-linear semi-analytical model for an all-elastomer, capacitive tactile unit-sensor is developed. The model is capable of predicting the response of such sensors over their entire sensing range under the application of normal forces. In doing so the [...] Read more.
In this work, a large deformation, non-linear semi-analytical model for an all-elastomer, capacitive tactile unit-sensor is developed. The model is capable of predicting the response of such sensors over their entire sensing range under the application of normal forces. In doing so the finite flat punch indentation model developed earlier is integrated with a capacitance model to predict the change-in-capacitance as a function of applied normal forces. The empirical change-in-capacitance expression, based on the parallel plate capacitance model, is developed to account for the fringe field and saturation effects. The elastomeric layer used as a substrate in these sensors is modeled as an incompressible, non-linear, hyperelastic material. More specifically, the two term Mooney-Rivlin strain energy function is used as a constitutive response to relate the stresses and strains. The developed model assumes both geometrical as well as material non-linearity. Based on the related experimental work presented elsewhere, the inverse analysis, combining finite element (FE) modeling and non-linear optimization, is used to obtain the Mooney-Rivlin material parameters. Finally, to validate the model developed herein the model predictions are compared to the experimental results obtained elsewhere for four different tactile sensors. Great agreements are found to exist between the two which shows the model capabilities in capturing the response of these sensors. The model and methodologies developed in this work, may also help advancing bio-material studies in the determination of biological tissue properties. Full article
(This article belongs to the Special Issue Sensors for MEMS and Microsystems)
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Open AccessArticle Kinematic Calibration of a Cable-Driven Parallel Robot for 3D Printing
Sensors 2018, 18(9), 2898; https://doi.org/10.3390/s18092898
Received: 20 July 2018 / Revised: 20 August 2018 / Accepted: 28 August 2018 / Published: 1 September 2018
Cited by 2 | PDF Full-text (8724 KB) | HTML Full-text | XML Full-text
Abstract
Three-dimensional (3D) printing technology has been greatly developed in the last decade and gradually applied in the construction, medical, and manufacturing industries. However, limited workspace and accuracy restrict the development of 3D printing technology. Due to the extension range and flexibility of cables, [...] Read more.
Three-dimensional (3D) printing technology has been greatly developed in the last decade and gradually applied in the construction, medical, and manufacturing industries. However, limited workspace and accuracy restrict the development of 3D printing technology. Due to the extension range and flexibility of cables, cable-driven parallel robots can be applied in challenging tasks that require motion with large reachable workspace and better flexibility. In this paper, a cable-driven parallel robot for 3D Printing is developed to obtain larger workspace rather than traditional 3D printing devices. A kinematic calibration method is proposed based on cable length residuals. On the basis of the kinematic model of the cable-driven parallel robot for 3D Printing, the mapping model is established among geometric structure errors, zero errors of the cable length, and end-effector position errors. In order to improve the efficiency of calibration measurement, an optimal scheme for measurement positions is proposed. The accuracy and efficiency of the kinematics calibration method are verified through numerical simulation. The calibration experiment based on the motion capture system indicates that the position error of end-effector is decreased to 0.6157 mm after calibration. In addition, the proposed calibration method is effective and verified for measurement positions outside optimal positions set through experiments. Full article
(This article belongs to the Special Issue Sensors for MEMS and Microsystems)
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Open AccessArticle Fabrication Technology and Characteristics Research of a Monolithically-Integrated 2D Magnetic Field Sensor Based on Silicon Magnetic Sensitive Transistors
Sensors 2018, 18(8), 2551; https://doi.org/10.3390/s18082551
Received: 9 June 2018 / Revised: 21 July 2018 / Accepted: 26 July 2018 / Published: 4 August 2018
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Abstract
A monolithically-integrated two-dimensional (2D) magnetic field sensor consisting of two difference structures (DSІ and DSII) is proposed in this paper. The DSІ and DSII are composed of four silicon magnetic sensitive transistors (SMST1, SMST2, SMST3 and SMST4) and four collector load resistors ( [...] Read more.
A monolithically-integrated two-dimensional (2D) magnetic field sensor consisting of two difference structures (DSІ and DSII) is proposed in this paper. The DSІ and DSII are composed of four silicon magnetic sensitive transistors (SMST1, SMST2, SMST3 and SMST4) and four collector load resistors (RL1, RL2, RL3 and RL4). Based on the magnetic sensitive principle of SMST, the integrated difference structure can detect magnetic fields’ component (Bx and By) along the x-axis and y-axis, respectively. By adopting micro-electromechanical systems (MEMS) and packaging technology, the chips were fabricated on a p-type <100> orientation silicon wafer with high resistivity and were packaged on printed circuit boards (PCBs). At room temperature, when the VCE = 5.0 V and IB = 8.0 mA, the magnetic sensitivities (Sxx and Syy) along the x-axis and the y-axis were 223 mV/T and 218 mV/T, respectively. The results show that the proposed sensor can not only detect the 2D magnetic field vector (B) in the xy plane, but also that Sxx and Syy exhibit good uniformity. Full article
(This article belongs to the Special Issue Sensors for MEMS and Microsystems)
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Open AccessArticle A Resonant Pressure Microsensor Based on Double-Ended Tuning Fork and Electrostatic Excitation/Piezoresistive Detection
Sensors 2018, 18(8), 2494; https://doi.org/10.3390/s18082494
Received: 19 June 2018 / Revised: 31 July 2018 / Accepted: 31 July 2018 / Published: 1 August 2018
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Abstract
This paper presents a resonant pressure microsensor relying on electrostatic excitation and piezoresistive detection where two double-ended tuning forks were used as resonators, enabling differential outputs. Pressure under measurement caused the deformation of the pressure sensitive membrane, leading to stress buildup of the [...] Read more.
This paper presents a resonant pressure microsensor relying on electrostatic excitation and piezoresistive detection where two double-ended tuning forks were used as resonators, enabling differential outputs. Pressure under measurement caused the deformation of the pressure sensitive membrane, leading to stress buildup of the resonator under electrostatic excitation with a corresponding shift of the resonant frequency detected piezoresistively. The proposed microsensor was fabricated by simplified SOI-MEMS technologies and characterized by both open-loop and closed-loop circuits, producing a quality factor higher than 10,000, a sensitivity of 79.44 Hz/kPa and an accuracy rate of over 0.01% F.S. In comparison to the previously reported resonant piezoresistive sensors, the proposed device used single-crystal silicon as piezoresistors, which was featured with low DC biased voltages, simple sensing structures and fabrication steps. In addition, the two double-ended tuning forks were used as resonators, producing high quality factors and differential outputs, which further improved the sensor performances. Full article
(This article belongs to the Special Issue Sensors for MEMS and Microsystems)
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Open AccessArticle Modeling and Analysis of a Novel Ultrasensitive Differential Resonant Graphene Micro-Accelerometer with Wide Measurement Range
Sensors 2018, 18(7), 2266; https://doi.org/10.3390/s18072266
Received: 5 June 2018 / Revised: 7 July 2018 / Accepted: 10 July 2018 / Published: 13 July 2018
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Abstract
A novel, ultrahigh-sensitivity wide-range resonant micro-accelerometer using two differential double-clamped monolayer graphene beams is designed and investigated by steady-state simulation via COMSOL Multiphysics software in this paper. Along with stiffness-enhanced optimized folded support beams, two symmetrical 3-GPa prestressed graphene nano-beams serve as resonant [...] Read more.
A novel, ultrahigh-sensitivity wide-range resonant micro-accelerometer using two differential double-clamped monolayer graphene beams is designed and investigated by steady-state simulation via COMSOL Multiphysics software in this paper. Along with stiffness-enhanced optimized folded support beams, two symmetrical 3-GPa prestressed graphene nano-beams serve as resonant sensitive elements with a size of 10 μm × 1 μm (length × width) to increase the acceleration sensitivity while extending the measurement range. The simulation results show that the accelerometer with cascade-connected graphene and proof-mass assembly exhibits the ultrahigh sensitivity of 21,224 Hz/g and quality factor of 9773 in the range of 0–1000 g. This is remarkably superior to previously reported studies characterized by attaching proof mass to the graphene components directly. The proposed accelerometer shows great potential as an alternative to quartz and silicon-based resonant sensors in high-impact and highly sensitive inertial measurement applications. Full article
(This article belongs to the Special Issue Sensors for MEMS and Microsystems)
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Open AccessArticle Real-Time Curvature Detection of a Flexible Needle with a Bevel Tip
Sensors 2018, 18(7), 2057; https://doi.org/10.3390/s18072057
Received: 25 April 2018 / Revised: 4 June 2018 / Accepted: 25 June 2018 / Published: 27 June 2018
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Abstract
As one of the major methods for the diagnosis and treatment of cancers in their early stages, the percutaneous puncture technique has bright prospect in biopsy, ablation, proximity radiotherapy, and drug delivery. Recent years, researchers found the flexible needle cannot realize feedback control [...] Read more.
As one of the major methods for the diagnosis and treatment of cancers in their early stages, the percutaneous puncture technique has bright prospect in biopsy, ablation, proximity radiotherapy, and drug delivery. Recent years, researchers found the flexible needle cannot realize feedback control during the puncture surgeries only by path planning. To solve this problem, the flexible needle is tried to achieve real-time detection in this paper. Compared with previous methods, the strain gauges glued on the needle surface rather than the medical imaging techniques is used to collect the information to reconstruct the needle curve, which is benefit to integrate the whole system and obtain a more simple and accurate closed-loop control. This paper presented the math model of curve fitting and analyzed the causes of curve fitting errors. To verify the feasibility of this method, an experiment setup was built. Results from the experiments validated the solution in this paper to be effective. Full article
(This article belongs to the Special Issue Sensors for MEMS and Microsystems)
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Open AccessArticle Reliability Evaluation and Robust Design of a Sensor in an Entire Roller-Embedded Shapemeter
Sensors 2018, 18(7), 1988; https://doi.org/10.3390/s18071988
Received: 27 April 2018 / Revised: 11 June 2018 / Accepted: 15 June 2018 / Published: 21 June 2018
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Abstract
The intermittence of the shape detection signal associated with an entire roller-embedded shapemeter roll, used in a seven-pass cold reversible rolling process, is considered. A transient interference at the sensor top surface and the distance between the sensor top surface and the roll [...] Read more.
The intermittence of the shape detection signal associated with an entire roller-embedded shapemeter roll, used in a seven-pass cold reversible rolling process, is considered. A transient interference at the sensor top surface and the distance between the sensor top surface and the roll outer surface are developed, and a sensor reliability evaluation model is derived. The reliability of the sensor is evaluated via the random perturbation method, and the reliability sensitivity of design variables is proposed. The analysis reveals that the reliability is smallest in the third rolling pass. Of the design variables considered, the initial interference exhibits the largest reliability sensitivity and has the greatest influence on the sensor reliability. A reliability robust design model of the initial interference is therefore developed. A new shapemeter roll is fabricated and tested in a 1050 reversible cold rolling mill. The test results are consistent with the theoretical results, thereby validating the proposed model. The selection of an appropriate initial interference provides an important means of overcoming the adverse effects associated with the thermal deformation of sensor contact surfaces. Full article
(This article belongs to the Special Issue Sensors for MEMS and Microsystems)
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Open AccessArticle Research on a Novel MEMS Sensor for Spatial DC Electric Field Measurements in an Ion Flows Field
Sensors 2018, 18(6), 1740; https://doi.org/10.3390/s18061740
Received: 10 April 2018 / Revised: 17 May 2018 / Accepted: 24 May 2018 / Published: 28 May 2018
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Abstract
Thus far, despite the development of electric field sensors (EFSs) such as field mills, optoelectronic EFSs and microelectromechanical system (MEMS)-based EFSs, no sensor can accurately measure an electric field in space due to the existence of space charge and the influence of charge [...] Read more.
Thus far, despite the development of electric field sensors (EFSs) such as field mills, optoelectronic EFSs and microelectromechanical system (MEMS)-based EFSs, no sensor can accurately measure an electric field in space due to the existence of space charge and the influence of charge attachment. To measure a spatial synthetic electric field in an ion flow field, a double potential independent differential EFS based on MEMS is proposed. Compared with other EFSs, this method has the advantages of independent potential (without grounding) and the ability to support the measurement of the synthetic ion flow electric field in space. First, to analyse the charge distribution after the sensor is involved exposed to an electric field, a simulation model was constructed. Then, given the redistribution of the spatial electric field in space and the influence of the surface charge on the sensor, the quantitative relationship between the electric field to be measured and that measured by the proposed sensor was obtained. To improve the performance of the EFS, a set of synthetic field strength sensor calibration systems that consider spatial ion flow injection was established. Furthermore, the parameter λ, which is related to the relative position of the differential chips, was determined. Finally, a series of comparative experiments indicated that the differential EFS highlighted in the present study exhibits good linearity and accuracy. Full article
(This article belongs to the Special Issue Sensors for MEMS and Microsystems)
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Open AccessArticle A 3D-Printed Multichannel Viscometer for High-Throughput Analysis of Frying Oil Quality
Sensors 2018, 18(5), 1625; https://doi.org/10.3390/s18051625
Received: 17 April 2018 / Revised: 12 May 2018 / Accepted: 16 May 2018 / Published: 19 May 2018
Cited by 1 | PDF Full-text (2655 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Viscosity as a sensitive measure of material changes is a potential quality-control parameter for simple and rapid assessment of frying oil quality. However, conventional viscometers require improvements in throughput, portability, cost-effectiveness and usability to be widely adopted for quality-control applications. Here we present [...] Read more.
Viscosity as a sensitive measure of material changes is a potential quality-control parameter for simple and rapid assessment of frying oil quality. However, conventional viscometers require improvements in throughput, portability, cost-effectiveness and usability to be widely adopted for quality-control applications. Here we present a 3D-printed multichannel viscometer for simple, inexpensive and multiplexed viscosity measurement. The multichannel viscometer enables both parallel actuation of multiple fluid flows by pressing the plunger of the viscometer by hand and direct measurement of their relative volumes dispensed with naked eye. Thus, the unknown viscosities of test fluids can be simultaneously determined by the volume ratios between a reference fluid of known viscosity and the test fluids of unknown viscosity. With a 4-plex version of the multichannel viscometer, we demonstrated that the viscometer is effective for rapid examination of the degradation of a vegetable oil during deep frying of potato strips and the recovery of used frying oil after treatment with an adsorbent agent to remove frying by-products. The measurement results obtained by the multichannel viscometer were highly correlated with those obtained using a commercial oil tester. We also demonstrated the multiplexing capability of the viscometer, fabricating a 10-plex version of the viscometer and measuring the viscosities of ten test liquids at the same time. Collectively, these results indicate that the 3D-printed multichannel viscometer represents a valuable tool for high-throughput examination of frying oil quality in resource-limited settings. Full article
(This article belongs to the Special Issue Sensors for MEMS and Microsystems)
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Open AccessArticle A Novel Model to Simulate Flexural Complements in Compliant Sensor Systems
Sensors 2018, 18(4), 1029; https://doi.org/10.3390/s18041029
Received: 10 January 2018 / Revised: 15 March 2018 / Accepted: 27 March 2018 / Published: 29 March 2018
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Abstract
The main challenge in analyzing compliant sensor systems is how to calculate the large deformation of flexural complements. Our study proposes a new model that is called the spline pseudo-rigid-body model (spline PRBM). It combines dynamic spline and the pseudo-rigid-body model (PRBM) to [...] Read more.
The main challenge in analyzing compliant sensor systems is how to calculate the large deformation of flexural complements. Our study proposes a new model that is called the spline pseudo-rigid-body model (spline PRBM). It combines dynamic spline and the pseudo-rigid-body model (PRBM) to simulate the flexural complements. The axial deformations of flexural complements are modeled by using dynamic spline. This makes it possible to consider the nonlinear compliance of the system using four control points. Three rigid rods connected by two revolute (R) pins with two torsion springs replace the three lines connecting the four control points. The kinematic behavior of the system is described using Lagrange equations. Both the optimization and the numerical fitting methods are used for resolving the characteristic parameters of the new model. An example is given of a compliant mechanism to modify the accuracy of the model. The spline PRBM is important in expanding the applications of the PRBM to the design and simulation of flexural force sensors. Full article
(This article belongs to the Special Issue Sensors for MEMS and Microsystems)
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Open AccessArticle EMD-Based Methodology for the Identification of a High-Speed Train Running in a Gear Operating State
Sensors 2018, 18(3), 793; https://doi.org/10.3390/s18030793
Received: 1 February 2018 / Revised: 1 March 2018 / Accepted: 4 March 2018 / Published: 6 March 2018
Cited by 12 | PDF Full-text (8281 KB) | HTML Full-text | XML Full-text
Abstract
An efficient maintenance is a key consideration in systems of railway transport, especially in high-speed trains, in order to avoid accidents with catastrophic consequences. In this sense, having a method that allows for the early detection of defects in critical elements, such as [...] Read more.
An efficient maintenance is a key consideration in systems of railway transport, especially in high-speed trains, in order to avoid accidents with catastrophic consequences. In this sense, having a method that allows for the early detection of defects in critical elements, such as the bogie mechanical components, is a crucial for increasing the availability of rolling stock and reducing maintenance costs. The main contribution of this work is the proposal of a methodology that, based on classical signal processing techniques, provides a set of parameters for the fast identification of the operating state of a critical mechanical system. With this methodology, the vibratory behaviour of a very complex mechanical system is characterised, through variable inputs, which will allow for the detection of possible changes in the mechanical elements. This methodology is applied to a real high-speed train in commercial service, with the aim of studying the vibratory behaviour of the train (specifically, the bogie) before and after a maintenance operation. The results obtained with this methodology demonstrated the usefulness of the new procedure and allowed for the disclosure of reductions between 15% and 45% in the spectral power of selected Intrinsic Mode Functions (IMFs) after the maintenance operation. Full article
(This article belongs to the Special Issue Sensors for MEMS and Microsystems)
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Open AccessArticle Structural Designing of a MEMS Capacitive Accelerometer for Low Temperature Coefficient and High Linearity
Sensors 2018, 18(2), 643; https://doi.org/10.3390/s18020643
Received: 14 December 2017 / Revised: 11 February 2018 / Accepted: 18 February 2018 / Published: 22 February 2018
Cited by 3 | PDF Full-text (4039 KB) | HTML Full-text | XML Full-text
Abstract
The low temperature coefficient and high linearity of the input-output characteristics are both required for high-performance microelectromechanical systems (MEMS) capacitive accelerometers. In this work, a structural designing of a bulk MEMS capacitive accelerometer is developed for both low temperature coefficient and high linearity. [...] Read more.
The low temperature coefficient and high linearity of the input-output characteristics are both required for high-performance microelectromechanical systems (MEMS) capacitive accelerometers. In this work, a structural designing of a bulk MEMS capacitive accelerometer is developed for both low temperature coefficient and high linearity. Firstly, the contrary effect of the wide-narrow gaps ratio (WNGR) on the temperature coefficient of the scale factor (TCSF) and linearity error is discussed. Secondly, the ability of an improved structure that can avoid the contrary effect is illustrated. The improved structure is proposed in our previous work for reducing the temperature coefficient of bias (TCB) and TCSF. Within the improved structure, both the TCSF and linearity error decrease with increasing WNGR. Then, the precise designing of the improved structure is developed for achieving lower TCB, TCSF, and linearity error. Finally, the precise structural designing is experimentally verified. Full article
(This article belongs to the Special Issue Sensors for MEMS and Microsystems)
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Open AccessArticle The Development and Test of a Sensor for Measurement of the Working Level of Gas–Liquid Two-Phase Flow in a Coalbed Methane Wellbore Annulus
Sensors 2018, 18(2), 579; https://doi.org/10.3390/s18020579
Received: 19 December 2017 / Revised: 6 February 2018 / Accepted: 8 February 2018 / Published: 14 February 2018
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Abstract
Coalbed methane (CBM) is one kind of clean-burning gas and has been valued as a new form of energy that will be used widely in the near future. When producing CBM, the working level within a CBM wellbore annulus needs to be monitored [...] Read more.
Coalbed methane (CBM) is one kind of clean-burning gas and has been valued as a new form of energy that will be used widely in the near future. When producing CBM, the working level within a CBM wellbore annulus needs to be monitored to dynamically adjust the gas drainage and extraction processes. However, the existing method of measuring the working level does not meet the needs of accurate adjustment, so we designed a new sensor for this purpose. The principle of our sensor is a liquid pressure formula, i.e., the sensor monitors the two-phase flow patterns and obtains the mean density of the two-phase flow according to the pattern recognition result in the first step, and then combines the pressure data of the working level to calculate the working level using the liquid pressure formula. The sensor was tested in both the lab and on site, and the tests showed that the sensor’s error was ±8% and that the sensor could function well in practical conditions and remain stable in the long term. Full article
(This article belongs to the Special Issue Sensors for MEMS and Microsystems)
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Open AccessArticle Design Optimization and Fabrication of a Novel Structural SOI Piezoresistive Pressure Sensor with High Accuracy
Sensors 2018, 18(2), 439; https://doi.org/10.3390/s18020439
Received: 9 January 2018 / Revised: 30 January 2018 / Accepted: 31 January 2018 / Published: 2 February 2018
Cited by 3 | PDF Full-text (5192 KB) | HTML Full-text | XML Full-text
Abstract
This paper presents a novel structural piezoresistive pressure sensor with four-grooved membrane combined with rood beam to measure low pressure. In this investigation, the design, optimization, fabrication, and measurements of the sensor are involved. By analyzing the stress distribution and deflection of sensitive [...] Read more.
This paper presents a novel structural piezoresistive pressure sensor with four-grooved membrane combined with rood beam to measure low pressure. In this investigation, the design, optimization, fabrication, and measurements of the sensor are involved. By analyzing the stress distribution and deflection of sensitive elements using finite element method, a novel structure featuring high concentrated stress profile (HCSP) and locally stiffened membrane (LSM) is built. Curve fittings of the mechanical stress and deflection based on FEM simulation results are performed to establish the relationship between mechanical performance and structure dimension. A combination of FEM and curve fitting method is carried out to determine the structural dimensions. The optimized sensor chip is fabricated on a SOI wafer by traditional MEMS bulk-micromachining and anodic bonding technology. When the applied pressure is 1 psi, the sensor achieves a sensitivity of 30.9 mV/V/psi, a pressure nonlinearity of 0.21% FSS and an accuracy of 0.30%, and thereby the contradiction between sensitivity and linearity is alleviated. In terms of size, accuracy and high temperature characteristic, the proposed sensor is a proper choice for measuring pressure of less than 1 psi. Full article
(This article belongs to the Special Issue Sensors for MEMS and Microsystems)
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