Results 1 - 10 of 18635
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[en] The field of cantilever-based sensing emerged in the mid-1990s and is today a well-known technology for label-free sensing which holds promise as a technique for cheap, portable, sensitive and highly parallel analysis systems. The research in sensor realization as well as sensor applications has increased significantly over the past 10 years. In this review we will present the basic modes of operation in cantilever-like micromechanical sensors and discuss optical and electrical means for signal transduction. The fundamental processes for realizing miniaturized cantilevers are described with focus on silicon- and polymer-based technologies. Examples of recent sensor applications are given covering such diverse fields as drug discovery, food diagnostics, material characterizations and explosives detection.
[en] Hydrogen sensors are transducer devices and able to convert the hydrogen concentration in the environment to an electrical signal. The detection and monitoring of hydrogen gas under the explosive limit is the essential issue for its applications as the chemical reactant and energy resource. In this study, the sensing mechanism and principle of the palladium-based hydrogen gas sensors are firstly reported. Then, the physical sensing parameter, measuring range, response time and recovery time of the different hydrogen gas sensors are also reviewed. Moreover, the high response speed hydrogen sensors are introduced for practical usages.
[en] This paper presents the analysis of a quasi-distributed sensor based on the concatenation of identical low-reflective fiber Bragg gratings. We experimentally demonstrated a temperature sensor using ten cascaded gratings which are interrogated by an optical frequency domain reflectometer. Repeatability measurements highlighted a standard deviation on the measured temperature smaller than 1.5 deg C. A complete demonstration of mathematical formulas which are used to obtain the temperature information is also provided
[en] A semi-analytical model for a double-plate capacitive proximity sensor is presented according to the effective theory. Three physical models are established to derive the final equation of the sensor. Measured data are used to determine the coefficients. The final equation is verified by using measured data. The average relative error of the calculated and the measured sensor capacitance is less than 7.5%. The equation can be used to provide guidance to engineering design of the proximity sensors
[en] Flexible sensors have received wide attention because of their ability to adapt to a variety of complex environments. Electrospinning technology has significant advantages in the preparation of flexible sensors. This paper summarizes the progress in the preparation of flexible sensors by electrospinning. Sensors that respond to light, stress, and gas are presented separately. Finally, some directions for electrospinning and flexible sensors are discussed. (paper)
[en] For monitoring the position and shape of fast moving and, especially, rotating objects such as turbo machine rotors, contactless and compact sensors with a high measurement rate as well as high precision are required. We present for the first time, to the best of our knowledge, a novel laser Doppler sensor employing a single fan-shaped interference fringe system, which allows measuring for the position and shape of fast moving solid bodies with known tangential velocity. It is shown theoretically as well as experimentally that this sensor offers concurrently high position resolution and high temporal resolution in contrast to conventional measurement techniques, since its measurement uncertainty is, in principle, independent of the object velocity. Moreover, it can be built very compact, because it features low complexity. To prove its operational capability and its potential for practical applications, radial and axial shape measurements of rotating bodies are demonstrated in comparison with triangulation. An average position resolution of about 2 μm could be achieved
[en] The Prototyping phase of the BAIKAL-GVD project has been started in April 2011 with the deployment of first autonomous engineering array which comprises all basic elements and systems of the Gigaton Volume Detector (GVD) in Lake Baikal. The prototyping phase will be concluded with deployment of the GVD demonstration cluster “DUBNA” in 2015, which will comprise 192 light sensors arranged at 8 strings. The first stage of the GVD demonstration cluster which consists of three strings was deployed in April 2013 and successfully operated up to February 2014. We review the prototyping phase of the BAIKAL-GVD project and describe the configuration and design of the 2013 engineering array.
[en] We designed a novel sensor specifically aimed at ex vivo measurements of white thrombus volume growth; a white thrombus is induced within an artificial micro-channel where hemostasis takes place starting from whole blood under flow conditions. The advantage of the proposed methodology is to identify the time evolution of the thrombus volume by means of an original data fusion methodology based on 2D optical and electrical impedance data simultaneously processed. On the contrary, the present state of the art optical imaging methodologies allow the thrombus volume estimation only at the end of the hemostatic process