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Sensor Devices (sensor + device)

Distribution by Scientific Domains

Polymers and Materials Science	37%
Engineering	37%

Selected Abstracts

A highly sensitive thermosensing CMOS Circuit Based on self-biasing circuit technique

IEEJ TRANSACTIONS ON ELECTRICAL AND ELECTRONIC ENGINEERING, Issue 2 2009
Tetsuya Hirose Non-memebr
Abstract A thermosensing CMOS circuit that changes its internal voltage steeply at a critical temperature was developed. The circuit is based on a self-biasing circuit technique and uses the temperature-sensitive characteristics of MOSFETs operating in the subthreshold region. To develop this sensor device, a method to analyze self-biasing circuits, which is different from a conventional one, was employed. This method is useful for understanding the self-biasing circuit operation. A temperature sensor device makes use of a MOSFET resistor's transition from a strong inversion to a weak-inversion or subthreshold operation. The temperature at which the transition occurs can be set to a desired value by adjusting the parameters of MOSFETs in the circuit. The sensor LSI can be made using a standard CMOS process and can be used as over-temperature and over-current protectors for LSI circuits. Copyright © 2009 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc. [source]

A Simple Optical Monitoring Technique for Determining the Geometrical Characteristics of a Plasma Jet

PLASMA PROCESSES AND POLYMERS, Issue 2 2006
Boyan E. Djakov
Abstract Summary: A sensor device is proposed to evaluate the location, size, and shape of a plasma jet. It consists of a small number (e.g., six) of photodetectors arranged in a cross-sectional plane of the jet. Tests of the technique are made by simulations based on CCD images of a plasma jet taken simultaneously from three different angles of view. Photodiode configuration [source]

UV Polymerisation of Surfactants Adsorbed at the Nematic Liquid Crystal,Water Interface Produces an Optical Response

CHEMPHYSCHEM, Issue 17 2009
Paul D. I. Fletcher Prof.
Abstract We have investigated the changes in crossed polariser optical textures produced by adsorption and UV polymerisation of a range of polymerisable surfactants at the interface between a nematic liquid crystal and water. Similar to non-polymerisable surfactants, the adsorption of polymerisable surfactants with sufficiently long hydrophobic tail groups produces a transition from planar to homeotropic anchoring. UV polymerisation of surfactants with a polymerisable group located in the hydrophobic tail region changes the anchoring from homeotropic back to planar. Polymerisation in the hydrophilic headgroup region does not produce an optical transition. We demonstrate that these systems can be used to "write with light" in the interfaces and that they form the basis of a UV sensor device in which the optical response is visible to the naked eye. [source]

Functionalized-Silk-Based Active Optofluidic Devices

ADVANCED FUNCTIONAL MATERIALS, Issue 7 2010
Konstantinos Tsioris
Abstract Silk protein from the silkworm Bombyx mori has excellent chemical and mechanical stability, biocompatibility, and optical properties. Additionally, when the protein is purified and reformed into materials, the biochemical functions of dopants entrained in the protein matrix are stabilized and retained. This unique combination of properties make silk a useful multifunctional material platform for the development of sensor devices. An approach to increase the functions of silk-based devices through chemical modifications to demonstrate an active optofluidic device to sense pH is presented. Silk protein is chemically modified with 4-aminobenzoic acid to add spectral-color-responsive pH sensitivity. The functionalized silk is combined with the elastomer poly(dimethyl siloxane) in a single microfluidic device. The microfluidic device allows spatial and temporal control of the delivery of analytic solutions to the system to provide the optical response of the optofluidic device. The modified silk is stable and spectrally responsive over a wide pH range from alkaline to acidic. [source]

Solid-State SO2 Sensor Using a Sodium-Ionic Conductor and a Metal,Sulfide Electrode

INTERNATIONAL JOURNAL OF APPLIED CERAMIC TECHNOLOGY, Issue 3 2006
Youichi Shimizu
All solid-state sulfur oxides (SOx) sensor devices combined with a sodium ionic conductor (Na5DySi4O12) disk and metal sulfide-sensing electrodes synthesized via solution routes have been systematically investigated for the detection of SO2 in the range of 20,200 ppm at 150,400°C. Among the various sulfide-sensing electrodes tested, the metal monosulfide-based electrodes gave good SO2 sensitivity at 400°C. The Pb1,xCdxS (x=0.1, 0.2)-based solid electrolyte sensor element showed the best sensing characteristics, i.e., the EMF response was almost linear to the logarithm of SO2 concentration in the range between 40 and 400 ppm, with a 90% response time to 100 ppm SO2 of about 3,15 min, and also showed high selectivity to SO2 at 400°C. [source]

An adaptive joining mechanism for improving the connection ratio of ZigBee wireless sensor networks

INTERNATIONAL JOURNAL OF COMMUNICATION SYSTEMS, Issue 2 2010
Tien-Wen Sung
Abstract Wireless sensor networks (WSNs) are well suited to many applications, including environment surveillance and target tracking. ZigBee is an IEEE 802.15.4-based standard that is considered suitable for WSNs. The functional operations of a ZigBee network rely on self-organized network connections and the proper deployment of sensor devices. However, the devices comprising a ZigBee network may become isolated from the network after the joining phase due to the configuration constraints of the ZigBee standard. This means that some deployed devices cannot join the network even though they can communicate with other joined nodes. These isolated devices reduce the efficiency of network operation and increase deployment costs. This paper proposes a ZigBee-compatible adaptive joining mechanism with connection shifting schemes to improve the connectivity of ZigBee networks, allowing them to operate at the expected efficiency. Simulation results show that the proposed mechanism significantly improves the join ratio of deployed sensor devices in ZigBee WSNs. Copyright © 2009 John Wiley & Sons, Ltd. [source]

WHOMoVeS: An optimized broadband sensor network for military vehicle tracking

INTERNATIONAL JOURNAL OF COMMUNICATION SYSTEMS, Issue 3 2008
Mohamed Hamdi
Abstract With the advance of sensing technologies and their applications, advanced sensor networks are gaining increasing interest. For certain sensitive applications, heterogeneous sensors can be deployed in the monitored space to ensure scalability, high-speed communication, and long network lifetime. Hybrid sensor networks have capabilities to combine the use of both resource-rich and resource-impoverished sensor nodes. This paper proposes a heterogeneous broadband sensor network architecture for military vehicle tracking. Powerful sensor devices with good bandwidth and energy capabilities are used as a communication backbone while energy sensors are used to track moving targets. Copyright © 2007 John Wiley & Sons, Ltd. [source]

Equilibrium Coverage Fluctuations: A New Approach to Quantify Reversible Adsorption of Proteins

CHEMPHYSCHEM, Issue 3 2005
Eike Lüthgens
Binding kinetics of proteins on sensor devices: A new approach to simultaneously determine the rate constants of adsorption and desorption of proteins on surfaces at low coverage from the power spectrum of equilibrium coverage fluctuations is proposed and verified by dynamic Monte Carlo simulations (see picture). [source]