Application Of Sensor System Research Articles

Label-free detection of single-stranded DNA binding protein based on a cantilever array

We report a simple and sensitive method for label-free detection of single-stranded DNA-binding protein (SSBP) based on an array of microfabricated cantilevers. The single-stranded DNA (ssDNA) was immobilized on the surface of the sensing cantilevers to detect SSBP, while the reference cantilevers were modified with 6-mercapto-1-hexanol to detect any unwanted cantilever deflection. The differential deflection signals that reveal specific SSBP–ssDNA binding have been found to depend on the SSBP concentration. Using the cantilever array sensor we can detect SSBP in the concentration range from 0.01 to 7μgmL−1. Other proteins, such as thrombin or bovine serum albumin induced no significant deflection of the cantilevers. Our results show the potential for the application of cantilever array sensor system as a powerful tool to detect proteins with high sensitivity and specificity.

DGS Rectenna를 이용한 Wake-Up 수신기 시스템 설계

본 논문에서는 저전력 센서를 위한 평면형 구조의 Rectenna 시스템을 설계하여 수신 센서의 wake-up 회로에 응용함으로써, 유효 주파수 신호의 입사시에만 동작되는 수신기 시스템을 제안하였다. 2.4 GHz 대역의 평면형집적이 가능한 Rectenna 시스템 설계를 위해 기존 여파기를 DGS 형태로 설계하여 다이오드에 의한 고조파 성분인 4.8 GHz, 7.2 GHz 신호를 제거와 DC-path를 위한 2.4 GHz 주 신호원의 제거를 수행하였다. 설계된 Rectenna의 변환 출력 전압 분석을 통해 수신시 시스템의 공급 전원의 스위칭 회로 구동에 활용함으로써 저전력 센서 수신 시스템의 동작 여부를 평가하였다. 제안된 시스템은 수신 센서의 신호 수신 여부에 따른 저 잡음 증폭기 동작점검에 의해 wake-up 성능이 평가되었으며, 실험 결과 우수한 동작 성능을 나타내었다. In this paper, a new design of a planar rectenna system and its application to a wake-up receiver operating for incoming signal with a specified frequency are proposed for low-power sensor system applications. The planar and integrable rectenna system is designed with DGSs(Defected Ground Structures) at 2.4 GHz. The DGSs reject harmonic components of 4.8 and 7.2 GHz and eliminate 2.4 GHz fundamental frequency for DC-path filtering. The rectenna system has been evaluated for the conversion output voltages, and applied to the switching of a power supply at the low-power sensor receivers. The proposed system has been evaluated for the wake-up performance by testing a lownoise amplifier operation. From the experimental results, the proposed receiver system presents excellent operation performances.

Cell-Based Sensor System Using L6 Cells for Broad Band Continuous Pollutant Monitoring in Aquatic Environments

Pollution of drinking water sources represents a continuously emerging problem in global environmental protection. Novel techniques for real-time monitoring of water quality, capable of the detection of unanticipated toxic and bioactive substances, are urgently needed. In this study, the applicability of a cell-based sensor system using selected eukaryotic cell lines for the detection of aquatic pollutants is shown. Readout parameters of the cells were the acidification (metabolism), oxygen consumption (respiration) and impedance (morphology) of the cells. A variety of potential cytotoxic classes of substances (heavy metals, pharmaceuticals, neurotoxins, waste water) was tested with monolayers of L6 cells (rat myoblasts). The cytotoxicity or cellular effects induced by inorganic ions (Ni2+ and Cu2+) can be detected with the metabolic parameters acidification and respiration down to 0.5 mg/L, whereas the detection limit for other substances like nicotine and acetaminophen are rather high, in the range of 0.1 mg/L and 100 mg/L. In a close to application model a real waste water sample shows detectable signals, indicating the existence of cytotoxic substances. The results support the paradigm change from single substance detection to the monitoring of overall toxicity.

무선 스마트센서를 이용한 사장교의 진동기반 구조건전성 모니터링

본 연구에서는 사장교의 구조건전성 모니터링을 위한 스마트 센서 시스템을 설계하고 그 적용성을 실물 장대 사장교를 대상으로 평가하였다. 본 연구는 세 단계로 구성되었다. 첫 번째로, 사장교의 주탑-케이블-덱 시스템의 상호 진동응답을 분석하였다. 두 번째로, 장대 사장교의 구조건전성 모니터링을 위한 Imote2 기반 스마트 센서 시스템을 설계하였다. 세 번째로, 실물 장대 사장교의 현장실험을 통해 스마트 센서 시스템의 적용성을 평가하였다. 대상 교량은 부산에 새로 건설된 화명대교이며, 대상 교량에 맞게 모니터링 시스템을 설계하고 센서 배치계획을 구성하였다. 일기 변화 조건에 대한 스마트 센서 시스템의 장기 모니터링 성능을 평가하였다. 교량의 진동응답을 계측하고 수치 모드해석결과와 비교하여 대상 교량의 진동모드특성을 식별하였다. 마지막으로, 진동응답신호를 이용하여 케이블 장력을 모니터링하였으며 그 정확도를 평가하였다. In this paper, the applicability of a smart sensor system for structural health monitoring (SHM) is evaluated on a full-scale cable-stayed bridge. Firstly, vibration responses of pylon-cable-deck system in cable-stayed bridge are described. Secondly, an Imote2-based smart sensor system is designed for the vibration-based SHM. Finally, the practicality of the smart sensor system is evaluated on a real cable-stayed bridge, Hwamyung Bridge in Korea. The field-test bridge is briefly described and the field sensor deployment is outlined. The long-term monitoring performance of the sensor system is examined under various weather conditions. The experimental modal parameters of the target bridge are identified by numerical modal analyses. The accuracy of cable force monitoring by the sensor system is evaluated for the target bridge.

Copper gives a lift

Gerald Küstler, an independent researcher from Germany, has experimentally shown that today's commercially available neodymium-iron-boron (NdFeB) magnets are powerful enough for stable levitation over weakly diamagnetic copper.This result may be useful in future sensor system applications, such as tiltmeters, seismometers, and accelerometers, where it is not possible to use the stronger diamagnetic materials of graphite or bismuth, or where a higher eddy current damping factor may be needed.

Wavelength Division Multiplexing/Spectral Amplitude Coding Applications in Fiber Vibration Sensor Systems

This paper presents a wavelength division multiplexing/spectral amplitude coding system with optical code-division multiple-access, for applications using fiber vibration sensors. The device makes use of fiber Bragg grating (FBG) etching on optical fibers to provide encoding/decoding functionality. According to the orthogonal properties of spectral amplitude coding (SAC) using m-sequence code, the encoding- decoding devices that employ FBG filters provide a considerable reduction in multiple access interference in optical code division multiple access systems. The proposed fiber vibration sensor located between the encoder and optical circulator enables the measurement of multiple points. Experimental results reveal that the proposed sensor detects a variety of vibrational signals.

Preparation and AFM-Characterization of Self-Assembled Monolayers Functionalized with a Thrombin Binding Aptamer

Self-assembled monolayers on silicon oxide surfaces functionalized with a unimolecular DNA G-quadruplex derived from the thrombin binding aptamer have been prepared. The formation of the G-quadruplex in the presence of potassium ions is observed by atomic force microscopy (AFM). The results presented here are interesting for the fabrication of nanostructured systems for sensing applications

Thin Film Transistors for Flexible Electronics: Contacts, Dielectrics and Semiconductors

The development of low temperature, thin film transistor processes that have enabled flexible displays also present opportunities for flexible electronics and flexible integrated systems. Of particular interest are possible applications in flexible sensor systems for unattended ground sensors, smart medical bandages, electronic ID tags for geo-location, conformal antennas, radiation detectors, etc. In this paper, we review the impact of gate dielectrics, contacts and semiconductor materials on thin film transistors for flexible electronics applications. We present our recent results to fully integrate hybrid complementary metal oxide semiconductors comprising inorganic and organic-based materials. In particular, we demonstrate novel gate dielectric stacks and semiconducting materials. The impact of source and drain contacts on device performance is also discussed.

Embedded distributed vision system for humanoid soccer robot

Computer vision is one of the most challenging applications in sensor systems since the signal is complex from spatial and logical point of view. Due to these characteristics vision applications require high computing resources, which makes them especially difficult to use in embedded systems, like mobile robots with reduced amount memory and computing power. In this work a distributed architecture for humanoid visual control is presented using specific nodes for vision processing cooperating with the main CPU to coordinate the movements of the exploring behaviours. This architecture provides additional computing resources in a reduced area, without disturbing tasks related with low level control (mainly kinematics) with the ones involving vision processing algorithms. The information is exchanged allowing to linking control loops between both nodes.

Remote sensing application system for water environments developed for Environment Satellite 1

Remote sensing data collected by the Environment Satellite I are characterized by high temporal resolution, high spectral resolution and mid-high spatial resolution. We designed the Remote Sensing Application System for Water Environments (RSASWE) to create an integrated platform for remote sensing data processing, parameter information extraction and thematic mapping using both remote sensing and GIS technologies. This system provides support for regional water environmental monitoring, and prediction and warning of water pollution. Developed to process and apply data collected by Environment Satellite I, this system has automated procedures including clipping, observation geometry computation, radiometric calibration, 6S atmospheric correction and water quality parameter inversion. RSASWE consists of six subsystems: remote sensing image processing, basic parameter inversion, water environment remote sensing thematic outputs, application outputs, automated water environment outputs and a non-point source pollution monitoring subsystem. At present RSASWE plays an important role in operations at the Satellite Environment Center.

Sensor array and stop-flow mode applied to discrimination and quantification of gas mixtures

The presented work focused on the strategy which offers widening the scope of applicability of sensor systems. The strategy was based on: (1) employing sensor array, which consists of many sensors, (2) applying stop-flow as the mode of sensor array operation, (3) utilizing response values of selected sensors measured at the same time point, (4) using only small fraction of obtained results. The performance of the system was evaluated with reference to the problems of discrimination of gas mixtures and quantification of their components. A considerable experimental material was the basis for our study. It comprised measurement results of 250 two-component VOC mixtures in air. They represented 10 classes characterized by fixed qualitative composition and variable quantitative one. The results of our work proved that sensor system based on big sensor array and operated in stop-flow mode has wider scope of application than the system utilizing small sensor array and one kind of exposure conditions.

Trends in Bragg Grating Technology for Optical Fiber Sensor Applications

Fiber Bragg gratings have found widespread and successful applications in optical sensor systems, e. g. for temperature, strain or refractive index measurements. Such sensor elements are fiber integrated, are applicable under harsh environmental conditions, and can be easily multiplexed. In order to further extend the field of applications, there is a great interest in specifically adapted Bragg gratings, in Bragg grating structures with increased stability, or in the use of special fiber types for grating inscription. The paper discusses such specific concepts for grating inscription, covers novel aspects of fiber gratings in small diameter fibers or in fiber tapers, of gratings in pure silica fibers without UV sensitivity, of grating inscription in different microstructured fibers or photonic crystal fibers, and investigates the concept of femtosecond inscription and the extension of the Bragg reflection wavelengths down to the visible range.

Integration of GaAs/In0.1Ga0.9As/AlAs resonance tunneling heterostructures into micro‐electro‐mechanical systems for sensor applications

AbstractDouble‐barrier quantum‐well resonant tunneling heterostructures of GaAs/In0.1Ga0.9As/AlAs have been used as pressure‐sensing elements of designed micro‐electro‐mechanical systems. The static experiments have been conducted on the heterostructure, in both positive and negative differential resistance (PDR and NDR) regions, showing a piezoresistive coefficient of 3.85 × 10−9 Pa−1, which is about seven times larger than that of piezoresistive silicon devices. At the same time, the devices also provided an improved dynamic response (119.6 µV · g−1 V−1) and signal‐to‐noise ratio (57 dB) in the NDR region.

Monitoring microstructure changes in rod online by using induction spectroscopy

This paper describes the application of a new multifrequency sensor system to an industrial rod mill. The system operates by analysing the response of the rod to an excitation signal which contains a range of frequencies. The sensor system is able to successfully monitor the transformation of the material. Sensor configurations that could be deployed online have been considered and a prototype system has been built and tested in the Stelmor section of the Scunthorpe Rod Mill fitted in the enhanced cooling zone. Initial results are shown, demonstrating that the phase spectra is essentially unaffected by variations in lift-off and the lay pattern of the rod on the run-out table. The system was also able to detect different phase spectra from different grades of steel and also to detect features of the process which are known to affect microstructure.

Cu based patch antenna on polymer substrate for flexible wireless sensor systems applications

In this work we designed, simulated and developed a flexible 10 GHz patch antenna using standard microsystem technology. Liquid crystal polymer (LCP) is used as substrate and Copper (Cu) as metallization thin film. LCP and Cu are best suited for high frequency applications because of their excellent electrical properties such as resistivity and dielectric constant. To protect the antenna it is passivated and encapsulated with parylene C. Parylene C was deposited at room temperature using standard Gorham system. The effect of Cu metallization and parylene C passivation on antenna indicator parameters such as resonance frequency, input reflection coefficient, bandwidth and gain are investigated. Furthermore the specific resistance of Cu lines on LCP substrates is investigated.

다중모드 광섬유 융착형 침수 감지 센서 개발

Abstract ： This paper reports a preliminary experimental investigation and characterization of an optical fiber-based submersion sensor sy stem for applications in water flooding and leakage. The sensor system comprises a multi-mode fiber spliced with fiber Bragg grating and an intensity-based interrogator. S ubmersion tests were conducted in water-air and Glycerin-air environments. By the re fractive index of the fiber-probe surrounding materials, the reflectance and the dete cting power level is determined. When the probe is dipped into the water, the optica l output power dramatically decreases from -7.5dBm to -17.5dBm. But, the cente r of Bragg wavelength is not affected in spite of external material changes. Temporal response characteristics of the sensor system is investigated to verify the real-time reaction. When the probe is immersed into the liquid, there is no transition time. Key words ：Fiber optic sensors (광섬유 센서), Submersion sensors ( 침수센서), Reflectance (반사도), Multi-mode fiber (다중모드 광섬유), Fiber Bragg grating (광섬유 브래그 격자)

Innovative High-Precision Position Sensor Systems for Robotic and Automotive Applications

Easily integrated high-precision position sensor systems manufactured by means of MEMS technologies are presented in this work. Two contactless working principles, inductive and capacitive, have been brought in operation successfully. The inductive sensors detect the direction of vector magnetic fields. Combined with permanent magnets, they are optimized for high-resolution angular measurements within the joints of parallel robots. The capacitive linear transducers measure the changing differential capacity caused by the displacement of a flexible electrode between two fixed electrodes during the actuation of a parallel micro robot. Fabrication, characteristics and applications of both sensor systems are discussed.

Composite S-layer lipid structures.

Designing and utilization of biomimetic membrane systems generated by bottom-up processes is a rapidly growing scientific and engineering field. Elucidation of the supramolecular construction principle of archaeal cell envelopes composed of S-layer stabilized lipid membranes led to new strategies for generating highly stable functional lipid membranes at meso- and macroscopic scale. In this review, we provide a state of the art survey how S-layer proteins, lipids, and polysaccharides may be used as basic building blocks for the assembly of S-layer supported lipid membranes. These biomimetic membrane systems are distinguished by a nanopatterned fluidity, enhanced stability and longevity and thus, provide a dedicated reconstitution matrix for membrane-active peptides and transmembrane proteins. Exciting areas for application of composite S-layer membrane systems concern sensor systems involving specific membrane functions.

Autonomous multi-sensor micro-system for measurement of ocean water salinity

This paper describes the design, fabrication and application of a micro-fabricated salinity sensor system. The theoretical electrochemical behaviour is described using electrical equivalent diagrams and simple scaling properties are investigated analytically and numerically using finite element method (FEM). The chip design and fabrication is described and measurement results of two different electrode designs are presented. The 4 mm × 4 mm multi-sensor allows for salinity determination with an accuracy of ± 0.5 psu through determination of the electrical conductivity, temperature and pressure with accuracies of ± 0.6 mS, ± 0.065 ° C and ± 0.05 bar, respectively.

Very broadband high frequency underwater acoustic communications

Many new applications for underwater observatories and sensor systems do not require long ranges, but do require very power‐efficient, high‐throughput communications. Recent work in phase‐coherent underwater acoustic communications has shown that signal bandwidths of 10‐40 khz at carrier frequencies from 80 to 120 khz may be used to achieve throughputs of up to 80 kbps at ranges of 100‐500 m in shallow water. The work has included channel impulse response measurements over time and with respect to range, and application of the adaptive decision feedback equalizer using signals at multiple bandwidths. The broadband, high‐frequency propagation environment is characterized, and its impact on the reliability of very wide band signals (relative to the signal carrier) is presented.