E-Mail Alert

Add your e-mail address to receive forthcoming issues of this journal:

Journal Browser

Journal Browser

Special Issue "Advances in Transducers"

Quicklinks

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

Deadline for manuscript submissions: closed (31 January 2010)

Special Issue Editor

Guest Editor
Prof. Dr. Soh Chee Kiong

Division of Structures and Mechanics, School of Civil and Environmental Engineering, Office N1-01a-26, College of Engineering, Nanyang Technological University, Singapore
Interests: piezo-impedance transducers; fiber optic sensors; ionic polymer metallic composites; damage prognosis; structural health monitoring; harvesting clean environmental energy

Special Issue Information

Dear Colleagues,

Transducers are devices which convert one form of energy or physical attribute into another for purposes such as measurement or information transfer. Basically, there are three kinds of transducers. The sensor is used to detect a parameter in one form of energy and report it in another form. The actuator is used to transform energy, generally from electrical into nonelectrical energy or vice versa. The third kind of transducer has both functions, and can switch between acting as an actuator and acting as a sensor. This special issue of SENSORS will report on the recent advances made in all kinds and types of transducers such as the electromagnetic transducers, electrochemical transducers, electromechanical transducers, electroacoustic transducers, photoelectric transducers, electrostatic transducers, thermoelectric transducers, radioacoustic transducers, fiber-optic transducers and biological transducers.

Prof. Dr. Soh Chee Kiong
Guest Editor

Keywords

  • transducers
  • sensors
  • actuators
  • energy
  • transduction
  • conversion
  • transformation
  • measurement
  • information transfer

Published Papers (12 papers)

View options order results:
result details:
Displaying articles 1-12
Export citation of selected articles as:

Research

Jump to: Review

Open AccessArticle A Reusable PZT Transducer for Monitoring Initial Hydration and Structural Health of Concrete
Sensors 2010, 10(5), 5193-5208; doi:10.3390/s100505193
Received: 19 March 2010 / Revised: 18 May 2010 / Accepted: 18 May 2010 / Published: 25 May 2010
Cited by 23 | PDF Full-text (827 KB) | HTML Full-text | XML Full-text
Abstract
During the construction of a concrete structure, strength monitoring is important to ensure the safety of both personnel and the structure. Furthermore, to increase the efficiency of in situ casting or precast of concrete, determining the optimal time of demolding is important [...] Read more.
During the construction of a concrete structure, strength monitoring is important to ensure the safety of both personnel and the structure. Furthermore, to increase the efficiency of in situ casting or precast of concrete, determining the optimal time of demolding is important for concrete suppliers. Surface bonded lead zirconate titanate (PZT) transducers have been used for damage detection and parameter identification for various engineering structures over the last two decades. In this work, a reusable PZT transducer setup for monitoring initial hydration of concrete and structural health is developed, where a piece of PZT is bonded to an enclosure with two bolts tightened inside the holes drilled in the enclosure. An impedance analyzer is used to acquire the admittance signatures of the PZT. Root mean square deviation (RMSD) is employed to associate the change in concrete strength with changes in the PZT admittance signatures. The results show that the reusable setup is able to effectively monitor the initial hydration of concrete and the structural health. It can also be detached from the concrete for future re-use. Full article
(This article belongs to the Special Issue Advances in Transducers)
Open AccessArticle Fiber Bragg Grating Sensor to Monitor Stress Kinetics in Drying Process of Commercial Latex Paints
Sensors 2010, 10(5), 4761-4776; doi:10.3390/s100504761
Received: 3 February 2010 / Revised: 25 April 2010 / Accepted: 28 April 2010 / Published: 11 May 2010
Cited by 5 | PDF Full-text (565 KB) | HTML Full-text | XML Full-text
Abstract
In this paper, we report a study about the application of packaged fiber Bragg gratings used as strain sensors to monitor the stress kinetics during the drying process of commercial latex paints. Three stages of drying with distinct mechanical deformation and temporal [...] Read more.
In this paper, we report a study about the application of packaged fiber Bragg gratings used as strain sensors to monitor the stress kinetics during the drying process of commercial latex paints. Three stages of drying with distinct mechanical deformation and temporal behaviors were identified for the samples, with mechanical deformation from 15 μm to 21 μm in the longitudinal film dimension on time intervals from 370 to 600 minutes. Drying time tests based on human sense technique described by the Brazilian Technical Standards NBR 9558 were also done. The results obtained shows that human sense technique has a limited perception of the drying process and that the optical measurement system proposed can be used to characterize correctly the dry-through stage of paint. The influence of solvent (water) addition in the drying process was also investigated. The paint was diluted with four parts paint and one part water (80% paint), and one part paint and one part water (50% paint). It was observed that the increase of the water ratio mixed into the paint decreases both the mechanical deformation magnitude and the paint dry-through time. Contraction of 5.2 μm and 10.4 μm were measured for concentrations of 50% and 80% of paint in the mixture, respectively. For both diluted paints the dry-through time was approximately 170 minutes less than undiluted paint. The optical technique proposed in this work can contribute to the development of new standards to specify the drying time of paint coatings. Full article
(This article belongs to the Special Issue Advances in Transducers)
Figures

Open AccessArticle Greatly Improved Small Inductance Measurement Using Quartz Crystal Parasitic Capacitance Compensation
Sensors 2010, 10(4), 3954-3960; doi:10.3390/s100403954
Received: 3 February 2010 / Revised: 23 March 2010 / Accepted: 23 March 2010 / Published: 20 April 2010
Cited by 9 | PDF Full-text (145 KB) | HTML Full-text | XML Full-text
Abstract
Generally, quartz crystal inductance frequency pulling in oscillators is very low and therefore is not often used in practice. The new method of improving frequencypullability uses inductance to compensate for quartz stray capacitances. To this end, a special AT fundamental quartz crystal [...] Read more.
Generally, quartz crystal inductance frequency pulling in oscillators is very low and therefore is not often used in practice. The new method of improving frequencypullability uses inductance to compensate for quartz stray capacitances. To this end, a special AT fundamental quartz crystal working near the antiresonance frequency is selected. By modifying its equivalent circuit with load inductance and series tuning capacitance, the magnetic sensing of the circuit can be highly improved. The experimental results show that the new approach using the quartz crystal stray capacitance compensation method increases the frequency pulling range (from ≅ 2 kHz/mH to ≅ 600 kHz/mH) by × 300 depending on the type of oscillator, making possible the measurement of nano-magnetic changes. Full article
(This article belongs to the Special Issue Advances in Transducers)
Open AccessArticle Carbon Nanotube Integration with a CMOS Process
Sensors 2010, 10(4), 3857-3867; doi:10.3390/s100403857
Received: 27 January 2010 / Revised: 6 April 2010 / Accepted: 9 April 2010 / Published: 15 April 2010
Cited by 2 | PDF Full-text (1111 KB) | HTML Full-text | XML Full-text
Abstract
This work shows the integration of a sensor based on carbon nanotubes using CMOS technology. A chip sensor (CS) was designed and manufactured using a 0.30 μm CMOS process, leaving a free window on the passivation layer that allowed the deposition of [...] Read more.
This work shows the integration of a sensor based on carbon nanotubes using CMOS technology. A chip sensor (CS) was designed and manufactured using a 0.30 μm CMOS process, leaving a free window on the passivation layer that allowed the deposition of SWCNTs over the electrodes. We successfully investigated with the CS the effect of humidity and temperature on the electrical transport properties of SWCNTs. The possibility of a large scale integration of SWCNTs with CMOS process opens a new route in the design of more efficient, low cost sensors with high reproducibility in their manufacture. Full article
(This article belongs to the Special Issue Advances in Transducers)
Open AccessArticle Wireless Health Data Exchange for Home Healthcare Monitoring Systems
Sensors 2010, 10(4), 3243-3260; doi:10.3390/s100403243
Received: 28 January 2010 / Revised: 4 March 2010 / Accepted: 15 March 2010 / Published: 1 April 2010
Cited by 14 | PDF Full-text (817 KB) | HTML Full-text | XML Full-text
Abstract
Ubiquitous home healthcare systems have been playing an increasingly significant role in the treatment and management of chronic diseases, such as diabetes and hypertension, but progress has been hampered by the lack of standardization in the exchange of medical health care information. [...] Read more.
Ubiquitous home healthcare systems have been playing an increasingly significant role in the treatment and management of chronic diseases, such as diabetes and hypertension, but progress has been hampered by the lack of standardization in the exchange of medical health care information. In an effort to establish standardization, this paper proposes a home healthcare monitoring system data exchange scheme between the HL7 standard and the IEEE1451 standard. IEEE1451 is a standard for special sensor networks, such as industrial control and smart homes, and defines a suite of interfaces that communicate among heterogeneous networks. HL7 is the standard for medical information exchange among medical organizations and medical personnel. While it provides a flexible data exchange in health care domains, it does not provide for data exchange with sensors. Thus, it is necessary to develop a data exchange schema to convert data between the HL7 and the IEEE1451 standard. This paper proposes a schema that can exchange data between HL7 devices and the monitoring device, and conforms to the IEEE 1451 standard. The experimental results and conclusions of this approach are presented and show the feasibility of the proposed exchange schema. Full article
(This article belongs to the Special Issue Advances in Transducers)
Open AccessArticle Design and Instrumentation of a Measurement and Calibration System for an Acoustic Telemetry System
Sensors 2010, 10(4), 3090-3099; doi:10.3390/s100403090
Received: 31 January 2010 / Revised: 20 February 2010 / Accepted: 23 March 2010 / Published: 31 March 2010
Cited by 21 | PDF Full-text (332 KB) | HTML Full-text | XML Full-text
Abstract
The Juvenile Salmon Acoustic Telemetry System (JSATS) is an active sensing technology developed by the U.S. Army Corps of Engineers, Portland District, for detecting and tracking small fish. It is used primarily for evaluating behavior and survival of juvenile salmonids migrating through [...] Read more.
The Juvenile Salmon Acoustic Telemetry System (JSATS) is an active sensing technology developed by the U.S. Army Corps of Engineers, Portland District, for detecting and tracking small fish. It is used primarily for evaluating behavior and survival of juvenile salmonids migrating through the Federal Columbia River Power System to the Pacific Ocean. It provides critical data for salmon protection and development of more “fish-friendly” hydroelectric facilities. The objective of this study was to design and build a Measurement and Calibration System (MCS) for evaluating the JSATS components, because the JSATS requires comprehensive acceptance and performance testing in a controlled environment before it is deployed in the field. The MCS consists of a reference transducer, a water test tank lined with anechoic material, a motion control unit, a reference receiver, a signal conditioner and amplifier unit, a data acquisition board, MATLAB control and analysis interface, and a computer. The fully integrated MCS has been evaluated successfully at various simulated distances and using different encoded signals at frequencies within the bandwidth of the JSATS transmitter. The MCS provides accurate acoustic mapping capability in a controlled environment and automates the process that allows real-time measurements and evaluation of the piezoelectric transducers, sensors, or the acoustic fields. The MCS has been in use since 2009 for acceptance and performance testing of, and further improvements to, the JSATS. Full article
(This article belongs to the Special Issue Advances in Transducers)
Open AccessArticle The Comparison of Environmental Effects on Michelson and Fabry-Perot Interferometers Utilized for the Displacement Measurement
Sensors 2010, 10(4), 2577-2586; doi:10.3390/s100402577
Received: 29 January 2010 / Revised: 10 March 2010 / Accepted: 16 March 2010 / Published: 24 March 2010
Cited by 10 | PDF Full-text (388 KB) | HTML Full-text | XML Full-text
Abstract
The optical structure of general commercial interferometers, e.g., the Michelson interferometers, is based on a non-common optical path. Such interferometers suffer from environmental effects because of the different phase changes induced in different optical paths and consequently the measurement precision will be [...] Read more.
The optical structure of general commercial interferometers, e.g., the Michelson interferometers, is based on a non-common optical path. Such interferometers suffer from environmental effects because of the different phase changes induced in different optical paths and consequently the measurement precision will be significantly influenced by tiny variations of the environmental conditions. Fabry-Perot interferometers, which feature common optical paths, are insensitive to environmental disturbances. That would be advantageous for precision displacement measurements under ordinary environmental conditions. To verify and analyze this influence, displacement measurements with the two types of interferometers, i.e., a self-fabricated Fabry-Perot interferometer and a commercial Michelson interferometer, have been performed and compared under various environmental disturbance scenarios. Under several test conditions, the self-fabricated Fabry-Perot interferometer was obviously less sensitive to environmental disturbances than a commercial Michelson interferometer. Experimental results have shown that induced errors from environmental disturbances in a Fabry-Perot interferometer are one fifth of those in a Michelson interferometer. This has proved that an interferometer with the common optical path structure will be much more independent of environmental disturbances than those with a non-common optical path structure. It would be beneficial for the solution of interferometers utilized for precision displacement measurements in ordinary measurement environments. Full article
(This article belongs to the Special Issue Advances in Transducers)
Open AccessArticle Capacitive Micro Pressure Sensor Integrated with a Ring Oscillator Circuit on Chip
Sensors 2009, 9(12), 10158-10170; doi:10.3390/s91210158
Received: 30 October 2009 / Revised: 17 November 2009 / Accepted: 23 November 2009 / Published: 14 December 2009
Cited by 31 | PDF Full-text (385 KB) | HTML Full-text | XML Full-text
Abstract
The study investigates a capacitive micro pressure sensor integrated with a ring oscillator circuit on a chip. The integrated capacitive pressure sensor is fabricated using the commercial CMOS (complementary metal oxide semiconductor) process and a post-process. The ring oscillator is employed to [...] Read more.
The study investigates a capacitive micro pressure sensor integrated with a ring oscillator circuit on a chip. The integrated capacitive pressure sensor is fabricated using the commercial CMOS (complementary metal oxide semiconductor) process and a post-process. The ring oscillator is employed to convert the capacitance of the pressure sensor into the frequency output. The pressure sensor consists of 16 sensing cells in parallel. Each sensing cell contains a top electrode and a lower electrode, and the top electrode is a sandwich membrane. The pressure sensor needs a post-CMOS process to release the membranes after completion of the CMOS process. The post-process uses etchants to etch the sacrificial layers, and to release the membranes. The advantages of the post-process include easy execution and low cost. Experimental results reveal that the pressure sensor has a high sensitivity of 7 Hz/Pa in the pressure range of 0–300 kPa. Full article
(This article belongs to the Special Issue Advances in Transducers)

Review

Jump to: Research

Open AccessReview Responsive Hydrogels for Label-Free Signal Transduction within Biosensors
Sensors 2010, 10(5), 4381-4409; doi:10.3390/s100504381
Received: 1 March 2010 / Revised: 12 April 2010 / Accepted: 23 April 2010 / Published: 30 April 2010
Cited by 33 | PDF Full-text (501 KB) | HTML Full-text | XML Full-text
Abstract
Hydrogels have found wide application in biosensors due to their versatile nature. This family of materials is applied in biosensing either to increase the loading capacity compared to two-dimensional surfaces, or to support biospecific hydrogel swelling occurring subsequent to specific recognition of [...] Read more.
Hydrogels have found wide application in biosensors due to their versatile nature. This family of materials is applied in biosensing either to increase the loading capacity compared to two-dimensional surfaces, or to support biospecific hydrogel swelling occurring subsequent to specific recognition of an analyte. This review focuses on various principles underpinning the design of biospecific hydrogels acting through various molecular mechanisms in transducing the recognition event of label-free analytes. Towards this end, we describe several promising hydrogel systems that when combined with the appropriate readout platform and quantitative approach could lead to future real-life applications. Full article
(This article belongs to the Special Issue Advances in Transducers)
Open AccessReview Phototactic and Chemotactic Signal Transduction by Transmembrane Receptors and Transducers in Microorganisms
Sensors 2010, 10(4), 4010-4039; doi:10.3390/s100404010
Received: 28 January 2010 / Revised: 29 March 2010 / Accepted: 9 April 2010 / Published: 20 April 2010
Cited by 14 | PDF Full-text (732 KB) | HTML Full-text | XML Full-text
Abstract
Microorganisms show attractant and repellent responses to survive in the various environments in which they live. Those phototaxic (to light) and chemotaxic (to chemicals) responses are regulated by membrane-embedded receptors and transducers. This article reviews the following: (1) the signal relay mechanisms [...] Read more.
Microorganisms show attractant and repellent responses to survive in the various environments in which they live. Those phototaxic (to light) and chemotaxic (to chemicals) responses are regulated by membrane-embedded receptors and transducers. This article reviews the following: (1) the signal relay mechanisms by two photoreceptors, Sensory Rhodopsin I (SRI) and Sensory Rhodopsin II (SRII) and their transducers (HtrI and HtrII) responsible for phototaxis in microorganisms; and (2) the signal relay mechanism of a chemoreceptor/transducer protein, Tar, responsible for chemotaxis in E. coli. Based on results mainly obtained by our group together with other findings, the possible molecular mechanisms for phototaxis and chemotaxis are discussed. Full article
(This article belongs to the Special Issue Advances in Transducers)
Open AccessReview Advanced Taste Sensors Based on Artificial Lipids with Global Selectivity to Basic Taste Qualities and High Correlation to Sensory Scores
Sensors 2010, 10(4), 3411-3443; doi:10.3390/s100403411
Received: 28 January 2010 / Revised: 29 March 2010 / Accepted: 30 March 2010 / Published: 8 April 2010
Cited by 87 | PDF Full-text (500 KB) | HTML Full-text | XML Full-text
Abstract
Effective R&D and strict quality control of a broad range of foods, beverages, and pharmaceutical products require objective taste evaluation. Advanced taste sensors using artificial-lipid membranes have been developed based on concepts of global selectivity and high correlation with human sensory score. These sensors respond similarly to similar basic tastes, which they quantify with high correlations to sensory score. Using these unique properties, these sensors can quantify the basic tastes of saltiness, sourness, bitterness, umami, astringency and richness without multivariate analysis or artificial neural networks. This review describes all aspects of these taste sensors based on artificial lipid, ranging from the response principle and optimal design methods to applications in the food, beverage, and pharmaceutical markets. Full article
(This article belongs to the Special Issue Advances in Transducers)
Figures

Open AccessReview Stress Sensors and Signal Transducers in Cyanobacteria
Sensors 2010, 10(3), 2386-2415; doi:10.3390/s100302386
Received: 20 January 2010 / Revised: 15 February 2010 / Accepted: 3 March 2010 / Published: 23 March 2010
Cited by 38 | PDF Full-text (403 KB) | HTML Full-text | XML Full-text
Abstract
In living cells, the perception of environmental stress and the subsequent transduction of stress signals are primary events in the acclimation to changes in the environment. Some molecular sensors and transducers of environmental stress cannot be identified by traditional and conventional methods. [...] Read more.
In living cells, the perception of environmental stress and the subsequent transduction of stress signals are primary events in the acclimation to changes in the environment. Some molecular sensors and transducers of environmental stress cannot be identified by traditional and conventional methods. Based on genomic information, a systematic approach has been applied to the solution of this problem in cyanobacteria, involving mutagenesis of potential sensors and signal transducers in combination with DNA microarray analyses for the genome-wide expression of genes. Forty-five genes for the histidine kinases (Hiks), 12 genes for serine-threonine protein kinases (Spks), 42 genes for response regulators (Rres), seven genes for RNA polymerase sigma factors, and nearly 70 genes for transcription factors have been successfully inactivated by targeted mutagenesis in the unicellular cyanobacterium Synechocystis sp. PCC 6803. Screening of mutant libraries by genome-wide DNA microarray analysis under various stress and non-stress conditions has allowed identification of proteins that perceive and transduce signals of environmental stress. Here we summarize recent progress in the identification of sensory and regulatory systems, including Hiks, Rres, Spks, sigma factors, transcription factors, and the role of genomic DNA supercoiling in the regulation of the responses of cyanobacterial cells to various types of stress. Full article
(This article belongs to the Special Issue Advances in Transducers)
Figures

Journal Contact

MDPI AG
Sensors Editorial Office
St. Alban-Anlage 66, 4052 Basel, Switzerland
sensors@mdpi.com
Tel. +41 61 683 77 34
Fax: +41 61 302 89 18
Editorial Board
Contact Details Submit to Sensors
Back to Top