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1
A room temperature acetone sensor based on synthesized tetranitro-oxacalix4arenes: Thin film fabrication and sensing properties
Dergi Makalesi

Dergi Makalesi
Kaynak 1:
DSpace Makaleler
Kaynak 2:
Science Direct
Yayıncı :
Sensors and Actuators, A: Physical
Yazar(lar) :
Sibel Şen , Ferah Cömert Önder , Rifat Çapan , Mehmet Ay
Konu :
Tetranitro-oxacalix4arene, Organic Thin Films, Surface Plasma Resonance, Weak Interactions, Acetone Sensing
Yıl :
2020
Sensors and Actuators, A: Physical
Kaydet
Çapan, Rifat (Balikesir Author) Tetranitro-oxacalix[4]arenes were prepared to determine their thin film fabrication and gas sensing applications. Firstly, tetranitro-oxacalix[4]arenes (1-3) were synthesized via nucleophilic aromatic sub-stitution reaction (SNAr) using substituted resorcinol derivatives and 1,5-difluoro-2,4-dinitrobenzene with moderate to high yields. Later, successfully synthesized materials were utilized to construct thin films using the spin coating method and the characterization of the deposited films was performed with UV-vis and surface plasmon resonance (SPR). Characterization results indicated that high-quality spin coated thin films were prepared using these materials. The sensing abilities of the spin-coated thin films of tetranitro-oxacalix[4]arenes (1-3) were tested using the SPR method for volatile organic vapours of acetone, chloroform, toluene, ethanol and benzene. High concentration sensitivity values of 0.0700 x 10(-3), 0.1001 x 10(-3) and 0.8653 x 10(-3) with normalized response/ppm unit for acetone vapour were obtained for thin films (1-3), respectively. The sensors obtained using especially thin films 1 and 3 showed high responses toward acetone even at low concentration ranges between 3.8-15.2 ppm. These sensors have the advantages of high sensitivity, reusability and reproducibility of results which make them compatible for practical acetone-detection applications.
Anahtar Kelimeler : Tetranitro-oxacalix4arene, Organic Thin Films, Surface Plasma Resonance, Weak Interactions, Acetone Sensing, article

ISSN: 0924-4247
2
The effect of periodic magnetic force on a piezoelectric energy harvester
Dergi Makalesi

Dergi Makalesi
Kaynak :
DSpace Makaleler
Yayıncı :
SENSORS AND ACTUATORS A-PHYSICAL
Yazar(lar) :
Yunus Uzun , Erol Kurt
Konu :
Energy harvester, Softening nonlinearity, Periodic magnetic force, Piezoelectric beam
Yıl :
2013
SENSORS AND ACTUATORS A-PHYSICAL
Yayıncı Web Sitesi
Kaydet
The response of a piezoelectric (PZT) harvester in pendulum shape is explored under a periodic magnetic field both theoretically and experimentally. The magnetic force F-m is found via fitting to a polynomial function including the third order of amplitude after the evaluation of magnetic simulations. F-m term dominates the dynamics of the piezoelectric (PZT) harvester with a certain frequency omega(m) and the excitation amplitude U-m. A clear softening effect is observed as function of excitation frequency. Besides, the output power estimation is in good agreement with the experimental results. While the amplitude changes sinusoidal, velocity of the pendulum tip especially includes a number of different high frequency components with growing amplitudes. The periodic excitation causes ripples at the maximal and minimal values of velocity. Excitation frequency omega(m) which differs from the natural frequency coo causes much complex velocity data with high frequency components. The averaged power P = 79 mu W can be obtained and power increases dramatically when the harvester is excited at the natural frequency. (C) 2012 Elsevier B.V. All rights reserved. Gazi University - Scientific Research Project UnitGazi University [BAP 07/2010-01]; TUBITAK Graduate School Programme ISMFATurkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [2217] The authors acknowledge the support of Gazi University - Scientific Research Project Unit under the Project no. BAP 07/2010-01 and the support of TUBITAK Graduate School Programme ISMFA 2011 under no: 2217.

ISSN: 0924-4247
3
Spectral analysis for photoacoustic pressure sensor designs: Theoretical model improvement and experimental validation
Dergi Makalesi

Dergi Makalesi
Kaynak :
DSpace Makaleler
Yayıncı :
SENSORS AND ACTUATORS A-PHYSICAL
Yazar(lar) :
Timucin Emre Tabaru , Sekip Esat Hayber , Serkan Keser , Omer Galip Saracoglu
Konu :
Pulsed laser photoacoustic method, Acoustic pressure sensor, Spectroscopy, Frequency domain solution, Photoacoustic wave equation, Theoretical model approach
Yıl :
2019
SENSORS AND ACTUATORS A-PHYSICAL
Yayıncı Web Sitesi
Kaydet
In the pulsed laser photoacoustic (PA) detection and spectroscopy applications, the fundamental frequency of the PA signal produced, and the sensor resonance frequency should be as close as possible to each other so that analyzes from the obtained signals can be performed effectively. In order to determine the fundamental frequency of the PA wave, a theoretical model approach based on the development of the frequency domain solution of the PA wave equation is presented for use in the PA pressure sensor designs. For the validation of the theoretical model approach, a PA experimental setup was established, and measurements were made in distilled water. The theoretical and the experimental PA frequency spectra were determined to be very compatible with each other. Thus, the theoretical model approach was experimentally validated. According to the theoretical model approach, fundamental frequency values obtained from the experimental measurement results were determined with an average accuracy of -/+ 4.212%. Furthermore, it has been determined that this value has fallen to -/+ 0.267% in the measurements. With the obtained results from the theoretical model approach, we propose that the PA pressure sensors with the more selective and narrower band can be designed for the more sensitive detection. Moreover, in this study the effects of different laser parameters such that pulse duration, and laser beam width, on the spectral content of the obtained PA signal are analyzed. These analyses will shed light on the vision of acoustic pressure sensor design by helping to select the most optimum parameters for the PA detection. (C) 2019 Elsevier B.V. All rights reserved. Research Fund of the Erciyes UniversityErciyes University [FDK-2016-6811, FDK-2016-6815] This work was supported by the Research Fund of the Erciyes University. Project numbers FDK-2016-6811 and FDK-2016-6815. The authors would like to thank Erciyes University Clinical Engineering Research and Application Center for their support in the research activities among the staffs.

ISSN: 0924-4247
Sınıflandırma :
Fizik %49
4
A simple analog behavioural model for NTC thermistors including selfheating effect
Dergi Makalesi

Dergi Makalesi
Kaynak :
DSpace Makaleler
Yayıncı :
Sensors and Actuators, A: Physical
Yazar(lar) :
A.U. Keskin
Konu :
Analog behavioural modeling, Circuit simulation, NTC thermistors, PSPICE
Yıl :
2005
Sensors and Actuators, A: Physical
Yayıncı Web Sitesi
Kaydet
In this paper, a model is presented to simulate loaded, as well as unloaded thermistors with negative temperature coefficients. This analog behavioural model (ABM) is particularly suitable for the steady-state large signal time-domain analysis and design of NTC thermistor circuits, making it possible to simulate complete static current-voltage characteristic of a thermistor element, including the effect of selfheating. © 2004 Elsevier B.V. All rights reserved.
Anahtar Kelimeler : Analog behavioural modeling, Circuit simulation, NTC thermistors, PSPICE, article

ISSN: 09244247
5
Production and characterisations of thin films deposited by a novel vacuum coating plant (VCP)
Dergi Makalesi

Dergi Makalesi
Kaynak :
DSpace Makaleler
Yayıncı :
Sensors and Actuators A-Physical
Yazar(lar) :
Hakan Köçkar , Turgut Meydan , Mürsel Alper , Elif Güngör
Konu :
Magnetic Anisotropy, Magnetic Properties Of Thin Films, Vacuum Coating
Yıl :
2006
Sensors and Actuators A-Physical
Yayıncı Web Sitesi
Kaydet
Köçkar, Hakan (Balıkesir Author) This paper reports a novel vacuum coating plant (VCP) system to prepare magnetic thin films. The first step of this extensive investigation was to evaporate and characterise simple iron films on various substrate in order to understand the process of deposition. The source material evaporated by a resistively heated furnace, which was position under the substrate within the VCP system, contains powdered iron of 99.0% in purity and 1-450 mu m in diameter. The magnetic and structural analysis of the films was achieved by using a vibrating sample magnetometer (VSM) and X-ray diffractometer (XRD), respectively, in order to see the effect of production conditions on the films. The magnetic findings indicate that the films produced on flexible kapton (TM) are anisotropic in the film plane whereas the films deposited on glass substrate indicate comparatively less-well defined anisotropy. All films showed planar magnetic anisotropy irrespective of type of substrate used. Furthermore, when these films are subjected to a bending stress within the VSM, the chances in their magnetic hysteresis loops occur. These results indicate a possible future for this technique to deposit sensing devices for stress detection. X-ray measurements show that the films have a typical body centred cubic (b.c.c.) alpha-iron crystal structure. The chemical compositions of films were confirmed by an inductively coupled plasma atomic emission spectrometry (ICP-AES).
Anahtar Kelimeler : Magnetic Anisotropy, Magnetic Properties Of Thin Films, Vacuum Coating, article

ISSN: 0924-4247
6
An investigation on the electromagnetic design optimization of rotary micromachines with double-layer permanent magnets
Dergi Makalesi

Dergi Makalesi
Kaynak :
DSpace Makaleler
Yayıncı :
Sensors and Actuators A, Physical
Yazar(lar) :
Kamil Yunus Özkaya , Mustafa İlker Beyaz
Konu :
Permanent magnet, Double-layer magnet design, Rotary micromachine, Micromotor, Spirometer, Sabit mıknatıs, Çift katmanlı mıknatıs tasarımı, Devir mikromekanik, Mikromotor, Solunumölçer
Yıl :
2015
Sensors and Actuators A, Physical
Yayıncı Web Sitesi
Kaydet
Electromagnetic design optimization of axial-flux rotary micromachines utilizing double-layer permanent magnets is presented and applied to a micro-scale generator/spirometer currently under development. Double-layer magnet configuration enables the use of two stators in a rotary micromachine, and hence offers performance enhancements in such devices. For an efficient transduction, number of magnetic poles should be carefully selected to obtain maximum flux density in a given device geometry, where magnetic reluctance and leakage act as two competing effects. This optimization has been performed through electromagnetic finite element simulations over a range of MEMS geometries. It was shown that the optimum number of magnetic poles varies from 22 to higher than 32 depending on specific magnet dimensions. Experiments on a manufactured magnet were performed and compared with simulation results. The analysis and results reported here shed light on the efficient design of magnetic micromachines in similar scales. No sponsor
7
Influence of deposition potentials applied in continuous and pulse waveforms on magnetic properties of electrodeposited nickel-iron films
Dergi Makalesi

Dergi Makalesi
Kaynak :
DSpace Makaleler
Yayıncı :
Sensors and Actuators A-Physical
Yazar(lar) :
Mürsel Alper , Hakan Köçkar , Hilal Kuru , Turgut Meydan
Konu :
Electrodeposition, Nife Films, Magnetic Anisotropy
Yıl :
2006
Sensors and Actuators A-Physical
Yayıncı Web Sitesi
Kaydet
Köçkar, Hakan (Balıkesir Author) The effect of the various cathode potentials applied in continuous and pulse waveforms on magnetic anisotropy of NiFe alloy films grown on (100) textured polycrystalline copper substrates has been studied. Magnetic measurements obtained by a vibrating sample magnetometer (VSM) showed that the magnetic anisotropy of the films is very sensitive to the cathode potentials and the type of the potentials applied during deposition. It was found that the easy axis of all films is in the film plane. The magnetic findings also indicated that the NiFe films deposited at the cathode potentials of - 1.2 and - 1.5 V applied in the continuous waveforms, but except for the films deposited at the cathode potential of - 1.8 V, are anisotropic, while those produced at the cathode potentials applied in the pulse waveform show an isotropic magnetic behaviour. Utilising the magnetic properties of the films may offer the potential for the development of a new range of stress sensors.
Anahtar Kelimeler : Electrodeposition, Nife Films, Magnetic Anisotropy, article

ISSN: 0924-4247
8
Direction finding of moving ferromagnetic objects inside water by magnetic anomaly
Dergi Makalesi

Dergi Makalesi Open Access
Kaynak :
DSpace Makaleler
Yayıncı :
Sensors and Actuators A-Physical
Yazar(lar) :
Yavuz Ege , Osman Kalender , Sedat Nazlıbilek
Konu :
Magnetic Anomaly, Remore Sensing, Magnetic Measurement, Scanning Systems
Yıl :
2008
Sensors and Actuators A-Physical
Yayıncı Web Sitesi Tam Metin
Kaydet
Ege, Yavuz (Balikesir Author) The remote sensing methods by the use of magnetic anomaly are gaining importance in applications of defense technologies and industrial purposes recently. In this study, it is aimed to determine the remote detection, the variation of characteristic of the voltage in the sensor relative to the motion, the effects of material length, magnetic permeability and direction of motion of the object on this characteristic and to convert them to a useful mathematical expression by using magnetic anomaly of ferromagnetic objects such as submarines moving inside water. For this purpose, first of all. a water tank of 1 m(3) is prepared and approximately a homogeneous magnetic field of 10(-3) T is created within this water tank. Ferromagnetic materials with six different lengths and permeabilities are moved in three different directions relative to the position of the sensor by means of a computer controlled x-y scanner designed for this experiment inside this magnetic field. The magnetic change Caused by this motion at the point where the sensor is positioned is detected as the Output voltage of the sensor. A mathematical expression is formulated taken into account the variations of the sensor output voltage with respect to the length, magnetic permeability and the direction of motion of the material and it is validated by the experimental results. This study clearly shows that the existence and the direction of motions of ferromagnetic objects with different lengths and magnetic permeabilities inside water can be detected with high accuracy. Olimed Ltd. Co.
Anahtar Kelimeler : Magnetic Anomaly, Remore Sensing, Magnetic Measurement, Scanning Systems, article

ISSN: 0924-4247
9
Non-destructive crack detection by capturing local flux leakage field
Dergi Makalesi

Dergi Makalesi Open Access
Kaynak :
DSpace Makaleler
Yayıncı :
Sensors and Actuators A-Physical
Yazar(lar) :
Mustafa Göktepe
Konu :
Non-Destructive, Crack Detection, Crack, Leakage Field, Sensor, Transducer
Yıl :
2001
Sensors and Actuators A-Physical
Yayıncı Web Sitesi Tam Metin
Kaydet
The crack detection in the industrial machine parts is very important. The non-destructive crack detection and evaluation of the these cracks are highly desirable from the viewpoint of safe and economic operation of installed facilities such as industrial factories and power plants. A crack induces local damages in the magnetic flux path in a ferromagnetic material and any change in crack area results in change in the distribution of magnetic flux in the material. In this paper, variation of the magnetic flux distribution in locally magnetised ferromagnetic materials which has discontinuity as a crack, is studied.
Anahtar Kelimeler : Non-Destructive, Crack Detection, Crack, Leakage Field, Sensor, Transducer, article

ISSN: 0924-4247
10
Editorial Board
Dergi Makalesi

Dergi Makalesi Open Access
Kaynak :
Science Direct
Yayıncı :
Sensors and Actuators A: Physical
Yıl :
2019
Sensors and Actuators A: Physical
Yayıncı Web Sitesi Tam Metin
Kaydet
DOI : 10.1016/S0924-4247(19)31314-7
Cilt: 295
Sayı: 0
Sayfa: ii-0
ISSN: 0924-4247
Sınıflandırma :
IOT %23
11
A real-time wearable emotion detection headband based on EEG measurement
Araştırma Makalesi

Araştırma Makalesi
Kaynak :
Science Direct
Yayıncı :
Sensors and Actuators A: Physical
Yazar(lar) :
Yang Wei , Yue Wu , John Tudor
Yıl :
2017
Sensors and Actuators A: Physical
Yayıncı Web Sitesi Tam Metin
Kaydet
A real-time emotion detection system based on electroencephalogram (EEG) measurement has been realised by means of an emotion detection headband coupled with printed signal acquisition electrodes and open source signal processing software (OpenViBE). Positive and negative emotions are the states classified and the Theta, Alpha, Beta and Gamma frequency bands are selected for the signal processing. It is found that, by using a combination of Power Spectral Density (PSD), Signal Power (SP) and Common Spatial Pattern (CSP) as the features, the highest subject-dependent accuracy (86.83%) and independent accuracy (64.73%) is achieved, when using Linear Discrimination Analysis (LDA) as the classification algorithm. The standard deviation of the results is 5.03. The electrode locations were then improved for the detection of emotion, by moving them from F1, F2, T3 and T4 to A1, F2, F7 and F8. The subject-dependent accuracy, using the improved locations, increased to 91.75% from 86.83% and 75% of participants achieved a classification accuracy higher than 90%, compared with only 16% of participants before improving the electrode arrangement.
DOI : 10.1016/j.sna.2017.07.012
Anahtar Kelimeler : Emotion sensing, EEG, Wearable, Printing, Real time
Cilt: 263
Sayı: 0
Sayfa: 614-621
ISSN: 0924-4247
Sınıflandırma :
12
Effect of spatial variations and desiccation cracks on the DPHP and MPHP sensors
Araştırma Makalesi

Araştırma Makalesi
Kaynak :
Science Direct
Yayıncı :
Sensors and Actuators A: Physical
Yazar(lar) :
Vinay S. Palaparthy , Somenath Mondal , Devendra N. Singh , Maryam Shojaei Baghini , G.K. Ananthasuresh
Yıl :
2018
Sensors and Actuators A: Physical
Yayıncı Web Sitesi Tam Metin
Kaydet
In sensing soil-moisture, there are inherent field related issues such as uncertainty and unpredictable distribution of minute amounts of trapped water and morphological changes of soil such as lumps and cracks due to desiccation. This poses problems for measurements done using a dual-probe heat-pulse (DPHP) technique that uses a narrow cylindrical sampling zone between heater and temperature probes. Thus, DPHP sensors are susceptible to errors. Hence, we studied and compared single-point and multi-point soil-moisture measurements using the heat-pulse technique. For this, we designed and developed a multi-point heat-pulse (MPHP) sensor with three temperature probes that enhanced the sampling zone to a volume of 840 mm3, which is three times that of the DPHP sensor. Sequentially deployed DPHP and MPHP sensors with spatial variations revealed that the maximum difference between the measured percentage of moisture from the DPHP sensor and standard oven-dried instrument was more than 10%, whereas for the MPHP sensor the discrepancy was only around 3%. Furthermore, when cracks appeared in the soil mass, it was observed that the discrepancy of DPHP sensor is around 16% while that for the MPHP sensor was still only 3%.
DOI : 10.1016/j.sna.2018.06.056
Anahtar Kelimeler : Dual-probe heat-pulse (DPHP) sensor, Multi-probe heat-pulse (MPHP) sensor, Soil moisture, Low power sensor
Cilt: 279
Sayı: 0
Sayfa: 638-648
ISSN: 0924-4247
Sınıflandırma :
Çevre %84
13
Multilayer ferroelectric thin films for pyroelectric applications
Araştırma Makalesi

Araştırma Makalesi
Kaynak :
Science Direct
Yayıncı :
Sensors and Actuators A: Physical
Yazar(lar) :
M Es-Souni , S Iakovlev , C.-H Solterbeck
Yıl :
2003
Sensors and Actuators A: Physical
Yayıncı Web Sitesi Tam Metin
Kaydet
High-quality multiplayer (ML) ferroelectric thin films based on erbium-doped lead titanate Pb(1−x)1.1ErxTi1−x/4O3 (PET) where x=0.05 and Pb1.1(Zr0.58Fe0.2Nb0.2Ti0.02)O3 (PZFNT) have been processed via chemical solution deposition on textured (1 1 1)Pt/Ti/SiO2/Si substrates. The dielectric, ferroelectric and pyroelectric properties are being characterised. It is shown that the multilayer film exhibits the relaxor type behaviour found for pure PZFNT, and that its transition temperature of 310 °C at 1 kHz lies between those of PET and PZFNT. The dielectric constant of 520 also lies between those of PET and PZFNT. The ferroelectric properties are considerably improved over those of the monomorph films. An unusually high pyroelectric coefficient of approximately 620 μC m−2 K−1 was obtained from measurements of the temperature dependence of the remnant polarisation between 30 and 80 °C. The voltage and current responses measured using a modulated near IR-laser, could be improved by 2–3 orders of magnitude over those of PZFNT. The thermal time constant τT obtained is found to be 3 orders of magnitude lower than the electrical time constant τE, and indicates that the high thermal conduction rate in the substrate determines the detector responsivity.
DOI : 10.1016/j.sna.2003.09.028
Anahtar Kelimeler : Chemical solution deposition, Multilayer films, Pyroelectric properties, Sensors
Cilt: 109
Sayı: 1-2
Sayfa: 114-119
ISSN: 0924-4247
Sınıflandırma :
14
Optimization of both Perturb & Observe and Open Circuit Voltage MPPT Techniques for Resonant Piezoelectric Vibration Harvesters feeding bridge rectifiers
Araştırma Makalesi

Araştırma Makalesi
Kaynak :
Science Direct
Yayıncı :
Sensors and Actuators A: Physical
Yazar(lar) :
Marco Balato , Luigi Costanzo , Alessandro Lo Schiavo , Massimo Vitelli
Yıl :
2018
Sensors and Actuators A: Physical
Yayıncı Web Sitesi Tam Metin
Kaydet
When the characteristics of the input vibrations change with time, also the optimal operating point of a Resonant Piezoelectric Vibration Energy Harvester (RPVEH) changes with time. Such an optimal operating point is characterized by the highest value of the extracted electrical power and is called Maximum Power Point (MPP). This paper is focused on MPP Tracking (MPPT) techniques for RPVEHs. In the most widespread RPVEH AC/DC architecture, which is based on the use of a diode bridge rectifier cascaded by a DC/DC converter, MPPT requires that the voltage V0 at the output of the bridge rectifier is properly regulated. The first issue that is addressed in this paper is the derivation of a simple closed form expression of the power extracted by a RPVEH as a function of the voltage V0 as well as of the optimal value of V0. Moreover, a complete set of general guidelines leading to the proper choice of the values of the parameters of the two most widely used MPPT techniques for RPVEHs applications (the Perturb & Observe technique and the Open Circuit Voltage technique) are provided and experimentally validated. It is experimentally shown that, if the above MPPT techniques are not properly and carefully customized to the particular RPVEH application of interest, they may lead to very poor performances of the system.
DOI : 10.1016/j.sna.2018.05.017
Anahtar Kelimeler : Piezoelectric vibration energy harvesters, Maximum power Point tracking techniques, Perturb and observe, Open circuit voltage
Cilt: 278
Sayı: 0
Sayfa: 85-97
ISSN: 0924-4247
15
Contactless liquid interface measurement based on a hollow coaxial cable resonator
Araştırma Makalesi

Araştırma Makalesi
Kaynak :
Science Direct
Yayıncı :
Sensors and Actuators A: Physical
Yazar(lar) :
Chen Zhu , Yiyang Zhuang , Yizheng Chen , Bohong Zhang , Jie Huang
Yıl :
2019
Sensors and Actuators A: Physical
Yayıncı Web Sitesi Tam Metin
Kaydet
This paper reports a contactless liquid interface sensor based on a microwave Fabry-Perot resonator. A hollow coaxial cable is employed as the sensing platform, in which air serves as the dielectric layer. By shorting the inner and outer conductors of the hollow coaxial cable, two reflectors with high reflectivity (>70%) are created to form a microwave Fabry-Perot resonator. An open groove is engineered on the resonator allowing the electromagnetic wave to interact with the medium outside the cavity. When a container, filled with different layers of liquids, is placed near the groove edge of the sensor, the leaked electromagnetic wave will interact with the liquids inside the container. By correlating the relative permittivity of the liquid mixture to the resonant frequency of the Fabry-Perot resonator, the interface between different liquids can be unambiguously determined. In the demonstration experiment, the water-oil interface and oil-ethanol interface were measured. Meanwhile, the sensor could also be employed to measure the relative permittivity of different liquids in a non-contact fashion. The presented sensor offers a robust, cost-effective, and real-time configuration for contactless liquid interface detection, which has potential applications in the oil and chemical industries.
DOI : 10.1016/j.sna.2018.12.003
Anahtar Kelimeler : Liquid interface, Hollow coaxial cable, Fabry-Perot resonator, Contactless measurement
Cilt: 285
Sayı: 0
Sayfa: 623-627
ISSN: 0924-4247
Sınıflandırma :
16
Automated sonic velocity calculation based on ultrasonic resonator measurements for on-line process monitoring
Araştırma Makalesi

Araştırma Makalesi
Kaynak :
Science Direct
Yayıncı :
Sensors and Actuators A: Physical
Yazar(lar) :
Marc Stanke , Patrick Lindner , Stephanie Holz , Bernd Hitzmann
Yıl :
2013
Sensors and Actuators A: Physical
Yayıncı Web Sitesi Tam Metin
Kaydet
Many applications of sonic velocity measurements for material testing are known and widely employed. Yet the technique is rarely employed in biotechnology especially for process monitoring. The ultrasonic resonator technology allows a highly precise measurement of the sonic velocity in small volumes, which makes this technology interesting for process analytics. New techniques give information about various process parameters on-line and in real time. Nowadays special interest is the on-line product analytic. Not only is the product concentration is in focus, but the purity and activity, which are currently rarely accessible on-line. The ultrasonic resonator is an opportunity to close this gap. An evaluation method will be introduced to ensure a maximum in precision and accuracy during the measurement. The best obtained precision of less than 0.3 mm s−1 sonic velocity and an accuracy of 0.027 m s−1, for water at different temperatures, give the possibility to detect slightest changes and recover worthwhile information during the measurements.
DOI : 10.1016/j.sna.2013.03.024
Anahtar Kelimeler : Ultrasonic resonator, Sonic velocity evaluation, Protein detection, Protein folding, On-line process monitoring
Cilt: 198
Sayı: 0
Sayfa: 69-74
ISSN: 0924-4247
Sınıflandırma :
Fizik %27
17
Flexible piezoelectric pressure sensor based on polydopamine-modified BaTiO3/PVDF composite film for human motion monitoring
Araştırma Makalesi

Araştırma Makalesi
Kaynak :
Science Direct
Yayıncı :
Sensors and Actuators A: Physical
Yazar(lar) :
Ye Yang , Hong Pan , Guangzhong Xie , Yadong Jiang , Chunxu Chen , Yuanjie Su , Yang Wang , Huiling Tai
Yıl :
2020
Sensors and Actuators A: Physical
Yayıncı Web Sitesi Tam Metin
Kaydet
Flexible pressure sensors based on piezoelectric materials have been intensively investigated for their wide applications in wearable electronics. However, traditional films based on inorganic/organic composite piezoelectric materials face the bottleneck of defects and cracks or poor dispersion, which hinders the performance of pressure sensors. Herein, polydopamine (PDA) was introduced as a surface modification agent to modify barium titanate (BaTiO3, BTO), which was then blended with poly(vinylidene fluoride) (PVDF) matrix in different ratios to form uniform and homogeneous [email protected]/PVDF composites. Afterwards, the flexible piezoelectric pressure sensor was fabricated by a facial solution-casting method. This PDA-modification strategy can improve the dispersion of BTO into PVDF matrix, as well as reduce the interface hole defects and cracks between the two components. As a result, the 17 wt% [email protected]/PVDF sensor exhibited a fast response of 61 ms and a remarkable piezoelectric output voltage of 9.3 V, which showed obvious improvement as compared to the pristine PVDF and BTO/PVDF composite counterparts. In addition, as an energy supplier, the sensor could produce a maximum power of 0.122 μW/cm2 even with high load resistance of 70 MΩ. This pressure sensor was sensitive to various human motions, showing great potential in the applications of wearable electronics.
DOI : 10.1016/j.sna.2019.111789
Anahtar Kelimeler : email protected/PVDF, Piezoelectric, Pressure sensor, Flexible, Motion monitoring
Cilt: 301
Sayı: 0
Sayfa: 111789-0
ISSN: 0924-4247
Sınıflandırma :
18
A CAD environment for the numerical simulation of integrated piezoresistive transducers
Araştırma Makalesi

Araştırma Makalesi
Kaynak :
Science Direct
Yayıncı :
Sensors and Actuators A: Physical
Yazar(lar) :
P. Ciampolini , A. Pierantoni , M. Rudan
Yıl :
1995
Sensors and Actuators A: Physical
Yayıncı Web Sitesi Tam Metin
Kaydet
This paper describes a CAD environment aimed at the simulation of (networks of) inntegrated piezoresistors. To this purpose, a stress-dependent mobility model has been worked out, in a form suitable for implementation in a semiconductor-device simulator. The code is linked to a structural simulator (MSC/NASTRAN), which provides accurate information on the distribution of stress within the simulation domain. Geometry, as well as boudary conditions, can be defined almost arbitrarily: geometrical flexibility is achieved by adopting three-dimensional, mixed-elements discretization grids. Simulation examples are presented, and the influence of some geometrical details on the response of piezoresistive pressure sensors is discussed.
DOI : 10.1016/0924-4247(94)00973-L
Anahtar Kelimeler : Computer-aided design, Piezoresistive tranducers
Cilt: 47
Sayı: 1-3
Sayfa: 618-622
ISSN: 0924-4247
Sınıflandırma :
19
Design and fabrication of a hybrid silicon three-axial force sensor for biomechanical applications
Araştırma Makalesi

Araştırma Makalesi
Kaynak :
Science Direct
Yayıncı :
Sensors and Actuators A: Physical
Yazar(lar) :
Lucia Beccai , Stefano Roccella , Alberto Arena , Francesco Valvo , Pietro Valdastri , Arianna Menciassi , Maria Chiara Carrozza , Paolo Dario
Yıl :
2005
Sensors and Actuators A: Physical
Yayıncı Web Sitesi Tam Metin
Kaydet
This paper presents the design and development of a silicon-based three-axial force sensor to be used in a flexible smart interface for biomechanical measurements. Normal and shear forces are detected by combining responses from four piezoresistors obtained by ion implantation in a high aspect-ratio cross-shape flexible element equipped with a 525 μm high silicon mesa. The mesa is obtained by a subtractive dry etching process of the whole handle layer of an SOI wafer. Piezoresistor size ranges between 6 and 10 μm in width, and between 30 and 50 μm in length. The sensor configuration follows a hybrid integration approach for interconnection and for future electronic circuitry system integration. The sensor ability to measure both normal and shear forces with high linearity (≅99%) and low hysteresis is demonstrated by means of tests performed by applying forces from 0 to 2 N. In this paper the packaging design is also presented and materials for flexible sensor array preliminary assembly are described.
DOI : 10.1016/j.sna.2005.01.007
Anahtar Kelimeler : Three-axial, Force, Microsensor, Hybrid, Biomechanics
Cilt: 120
Sayı: 2
Sayfa: 370-382
ISSN: 0924-4247
Sınıflandırma :
20
A review of optical actuators and the impact of micromachining
Araştırma Makalesi

Araştırma Makalesi
Kaynak :
Science Direct
Yayıncı :
Sensors and Actuators A: Physical
Yazar(lar) :
B.E. Jones , J.S. McKenzie
Yıl :
1993
Sensors and Actuators A: Physical
Yayıncı Web Sitesi Tam Metin
Kaydet
Optically powered fluid actuators are under development, for example, those using the photoacoustic and photothermal effects in closed cells and laminar proportional amplifiers (LPA). A number of the devices could be improved by a reduction in size of certain elements of the actuators, and already silicon micromachining is enabling this miniaturization to be achieved. Some important optical actuators and effects are reviewed in this paper and the prospects for improvements are discussed.
DOI : 10.1016/0924-4247(93)80035-F
Cilt: 37-38
Sayı: 0
Sayfa: 202-207
ISSN: 0924-4247
Sınıflandırma :
21
Fabrication of high-resolution strain sensors based on wafer-level vacuum packaged MEMS resonators
Araştırma Makalesi

Araştırma Makalesi
Kaynak :
Science Direct
Yayıncı :
Sensors and Actuators A: Physical
Yazar(lar) :
Luca Belsito , Matteo Ferri , Fulvio Mancarella , Luca Masini , Jize Yan , Ashwin A. Seshia , Kenichi Soga , Alberto Roncaglia
Yıl :
2016
Sensors and Actuators A: Physical
Yayıncı Web Sitesi Tam Metin
Kaydet
The paper reports on the fabrication and characterization of high-resolution strain sensors for structural materials based on Silicon On Insulator flexural resonators manufactured by polysilicon Low-Pressure Chemical Vapour Deposition vacuum packaging. The sensors present sensitivity of 164 Hz/με and strain resolution limit of 150 pε on steel for a measurement time of 315 ms, in both tensile and compressive strain regimes. The readout of the sensor is implemented with a transimpedance oscillator circuit implemented on Printed Circuit Board, in which a microcontroller-based reciprocal frequency counter is integrated. The performance of the sensors on steel are investigated for measurement bandwidths from 1.5 to 500 Hz and a comparison with conventional metal strain gauges is proposed.
DOI : 10.1016/j.sna.2016.01.006
Anahtar Kelimeler : Strain sensor, Resonator, SOI, MEMS, Wafer-level vacuum packaging
Cilt: 239
Sayı: 0
Sayfa: 90-101
ISSN: 0924-4247
Sınıflandırma :
22
Structural optimization of contact electrodes in microbial fuel cells for current density enhancements
Araştırma Makalesi

Araştırma Makalesi
Kaynak :
Science Direct
Yayıncı :
Sensors and Actuators A: Physical
Yazar(lar) :
Shogo Inoue , Erika A. Parra , Adrienne Higa , Yingqi Jiang , Pengbo Wang , Cullen R. Buie , John D. Coates , Liwei Lin
Yıl :
2012
Sensors and Actuators A: Physical
Yayıncı Web Sitesi Tam Metin
Kaydet
More than 200% current density enhancement in miniaturized microbial fuel cells (MFCs) has been successfully demonstrated by optimizing the contact electrode structure using micro and nano features. Two fundamental issues are addressed in this work: (1) a methodology to enhance current/power density of MFCs by changing micro and nano structural configurations of contact electrodes and (2) a study on the effectiveness of charge transfer between living cells with organic nanowire-pili and micro/nano interfacial electrodes. This paper details the fabrication and characterization processes of miniaturized MFCs with experimental results, and discusses the prospective power density of MFCs using micro/nano processes. Moreover, a hypothesis for the direct electron transport mechanism from living cells to electrodes is experimentally corroborated. As such, this work represents a step toward higher energy conversion efficiency as well as practical applications of MFCs.
DOI : 10.1016/j.sna.2011.09.023
Anahtar Kelimeler : Microbial fuel cell, Current density, Power density, Carbon nanotube, Geobacter sulfurreducens
Cilt: 177
Sayı: 0
Sayfa: 30-36
ISSN: 0924-4247
Sınıflandırma :
23
Design and fabrication of novel three-dimensional multi-electrode array using SOI wafer
Araştırma Makalesi

Araştırma Makalesi
Kaynak :
Science Direct
Yayıncı :
Sensors and Actuators A: Physical
Yazar(lar) :
Huai-Yuan Chu , Tzu-Ying Kuo , Baowen Chang , Shao-Wei Lu , Chuan-Chin Chiao , Weileun Fang
Yıl :
2006
Sensors and Actuators A: Physical
Yayıncı Web Sitesi Tam Metin
Kaydet
A novel method has been developed for the manufacture of a three-dimensional multi-electrode array (3D MEA), particularly, the shape of micro-tips can be varied by MEMS technology to construct different multi-electrode array. It improved the disadvantage of single electrode, which meant that it was available for multi-recording and analysis of a series of signals. Overcoming the difficulty of making interconnection line on 3D MEA chips via innovative fabrication process design. Using local isolation and removal of oxide films to forming electrodes and interconnections with oxide isolation covers. A 10 × 10 3D MEA with a distance of 100 μm between each other for further bio-neural signals was demonstrated, and a test on rabbit retina was also available. Besides, integrating pre-amplifier and built-in resistors with 3D MEA was brought out to hopefully increase the efficiency of sensing.
DOI : 10.1016/j.sna.2006.02.010
Anahtar Kelimeler : 3D Multi-electrode array, Recording of retinal neurons, SOI wafer
Cilt: 130-131
Sayı: 0
Sayfa: 254-261
ISSN: 0924-4247
Sınıflandırma :
24
Gradual oxidation of stain etched porous silicon nanostructures applied to silicon-based solar cells
Araştırma Makalesi

Araştırma Makalesi
Kaynak :
Science Direct
Yayıncı :
Sensors and Actuators A: Physical
Yazar(lar) :
B. González-Díaz , R. Guerrero-Lemus , J. Méndez-Ramos , B. Díaz-Herrera , V.D. Rodríguez
Yıl :
2009
Sensors and Actuators A: Physical
Yayıncı Web Sitesi Tam Metin
Kaydet
This work describes the photoluminescence (PL) and morphology of stain etched porous silicon nanostructures (PSN) submitted to a gradual oxidation by immersion in a HNO3 boiling point solution and applied to solar cells. The gradual oxidation passivates the extremely reactant fresh porous surface and softens the porous structure for an adequate placement of the metallic contact on top. The pore size and the porosity of the samples have been evaluated by means of the Brunauer, Emmett and Teller (BET) technique. The surface morphology has been analyzed by atomic forces microscopy. The oxidation process of the layers has been evaluated using a Fourier transform infrared spectrometer (FTIR), analyzing the evolution of the Si–O, Si–H and Si–OH absorption bands. It is found a blueshift in the PL spectra attributed to the oxidation process which increases the photoconversion properties of the nanostructures. An efficiency of 15.2% and fill factor (FF) of 80.5% were found.
DOI : 10.1016/j.sna.2008.12.006
Anahtar Kelimeler : Porous silicon, Solar cells, Oxidation, Luminescence
Cilt: 150
Sayı: 1
Sayfa: 97-101
ISSN: 0924-4247
Sınıflandırma :
25
Vapomechanical soft actuators based on graphene-polymer Nanocomposite/Metal hybrid structure for visual detection of chloroform
Dergi Makalesi

Dergi Makalesi
Kaynak :
Science Direct
Yayıncı :
Sensors and Actuators A: Physical
Yıl :
2019
Sensors and Actuators A: Physical
Yayıncı Web Sitesi Tam Metin
Kaydet
Vapomechanical actuation triggered through chemical vapors by employing soft smart materials is the most recent and less-explored area of actuators research having powerful applications in the field of chemical sensors/detectors. A tubular shaped actuator driven by chloroform vapors based on graphene-polydimethylsiloxane nanocomposite/gold bilayers has been realized. The tubular shape of actuator is transformed into a planar sheet within about 1.7 s time under the exposure of chloroform vapors with vapor pressure of 57 kPa. The shape switching time of this actuator varies linearly with vapor pressure of chloroform. These vapomechanical actuators may find potential uses in the development of smart chemical sensors which are cheap, easy to use and do not require any electrical power for their operations.
DOI : 10.1016/j.sna.2019.07.006
Anahtar Kelimeler : Graphene, Vapomechanical actuators, Nanocomposite, Polydimethylsiloxane
Cilt: 296
Sayı: 0
Sayfa: 87-91
ISSN: 0924-4247
Sınıflandırma :
26
Acoustically generated flows in microchannel flexural plate wave sensors: Effects of compressibility
Araştırma Makalesi

Araştırma Makalesi
Kaynak :
Science Direct
Yayıncı :
Sensors and Actuators A: Physical
Yazar(lar) :
Ersin Sayar , Bakhtier Farouk
Yıl :
2011
Sensors and Actuators A: Physical
Yayıncı Web Sitesi Tam Metin
Kaydet
Acoustically generated flowfields in flexural plate wave sensors filled with a Newtonian liquid (water) are considered. A computational model based on compressible flow is developed for the sensor with a moving wall for pumping and mixing applications in microchannels. For the compressible flow formulation, an isothermal equation of state for water is employed. The velocity and pressure profiles for different parameters including flexural wall frequency, channel height, amplitude of the wave and wave length are investigated for four microchannel height/length geometries. It is found that the flowfield becomes pseudo-steady after sufficient number of flexural cycles. Both instantaneous and time averaged results show that an evanescent wave is generated in the microchannel. The predicted flows generated by the FPWs are compared with results available in the literature. The proposed device can be exploited to integrate micropumps with complex microfluidic chips improving the portability of micro-total-analysis systems.
DOI : 10.1016/j.sna.2011.08.018
Anahtar Kelimeler : Flexural plate wave (FPW), Acoustic streaming, Microchannel, Micropump, Acoustic waves, Fluid damping, Lamb wave
Cilt: 171
Sayı: 2
Sayfa: 317-323
ISSN: 0924-4247
Sınıflandırma :
27
A miniaturized wireless control platform for robotic capsular endoscopy using advanced pseudokernel approach
Araştırma Makalesi

Araştırma Makalesi
Kaynak :
Science Direct
Yayıncı :
Sensors and Actuators A: Physical
Yazar(lar) :
E. Susilo , P. Valdastri , A. Menciassi , P. Dario
Yıl :
2009
Sensors and Actuators A: Physical
Yayıncı Web Sitesi Tam Metin
Kaydet
A ZigBee compliant wireless controller which manages multiple tasks, such as acquiring data from sensors and driving actuators, has been purposely developed for robotic capsular endoscopy applications. Preemptive priority pseudokernel, consisting of state-driven code, coroutine, and pooled-loop algorithm, has been implemented to perform hard, firm and soft real time applications. All the components have been placed on a miniaturized board ready to be integrated in a robotic capsule (max volume of 2 cm3).
DOI : 10.1016/j.sna.2009.03.036
Anahtar Kelimeler : Pseudokernel, Real time embedded system, Robotic capsular endoscopy, Wireless miniaturized control board
Cilt: 156
Sayı: 1
Sayfa: 49-58
ISSN: 0924-4247
Sınıflandırma :
28
Flow rate influencing effects of micropumps
Araştırma Makalesi

Araştırma Makalesi
Kaynak :
Science Direct
Yayıncı :
Sensors and Actuators A: Physical
Yazar(lar) :
C. Jenke , S. Kager , M. Richter , C. Kutter
Yıl :
2018
Sensors and Actuators A: Physical
Yayıncı Web Sitesi Tam Metin
Kaydet
Current micropump technology features bubble tolerance and self-priming ability, achieved with high pressure ability at shallow pump chambers for low dead volume and high compression ratio. Though, the pump dynamics are strongly affected by a pump chamber height dependent viscous squeeze film damping. Therefore, we investigated all major flow influencing effects for micro diaphragm pumps, being liquid resistive damping, cavitation based gaseous capacitive damping and reactive valve volumes. Analytical models were developed that are able to describe and predict the transient actuator displacement, derive the frequency dependent displacement and estimate the valve loss effect in order to determine the flow rate performance of micropumps. In addition, a new oscillator model is able to simulate the inception of cavitation and the time course of both actuator and liquid. The individual effect models were combined into a single-cycle based, frequency dependent, flow rate model, validated for frequencies of up to 100 Hz. Compared to the maximum achievable flow rate, the liquid resistive damping reduces dynamic stroke volume and is responsible for a reduction of 23–57 % at 100 Hz. Valve induced flow losses reduce the effectively redirected volume towards the outlet. The effect is enhanced by the strong damping, but also feeds back on the actuator by reducing initial damping significantly. Reactive valve volumes amount for 6.2–12.4% flow rate reduction at 100 Hz. Full cavitation, generated at the supply mode and affecting the pump mode, can cause gas bubble generation and lead to a drop of flow rate down to 65% at 80 Hz. By placing an in-line degasser the flow stability was improved to ±2.2% over 10 h. After reducing the frequency to 20 Hz, cavitation only affected the supply mode and in combination with a degasser a flow stability of ±0.15% over 2 h was achieved. By reducing voltage levels, cavitation was avoided completely, featuring a stability of ±0.08%. The understanding of the flow rate limiting effects enables the application specific design to meet all performance and reliability requirements for micropump based liquid dosing systems.
DOI : 10.1016/j.sna.2018.04.025
Cilt: 276
Sayı: 0
Sayfa: 335-345
ISSN: 0924-4247
Sınıflandırma :
29
Monitoring photo-polymerization of thin films using SH acoustic plate mode sensors
Araştırma Makalesi

Araştırma Makalesi
Kaynak :
Science Direct
Yayıncı :
Sensors and Actuators A: Physical
Yazar(lar) :
S.J. Martin , A.J. Ricco
Yıl :
1990
Sensors and Actuators A: Physical
Yayıncı Web Sitesi Tam Metin
Kaydet
The use of shear-horizontal (SH) acoustic plate mode (APM) devices to monitor the cross-linking of polymer films in real time has been demonstrated. The SH-APM, which is excited and detected in a thinned quartz plate by interdigital transducers patterned on the surface, has displacement in the plane of the surface and normal to the direction of mode propagation. Because APM propagation velocity is affected by the shear stiffness (but not the bulk modulus) of a thin film in contact with the device surface, the APM acts as a sensitive probe of this film property. Using an APM sensor, the changes in shear modulus which accompany the photocross-linking of a negative photoresist polymer film were monitored as a function of time and of the wavelength of the cross-linking radiation.
DOI : 10.1016/0924-4247(89)80064-0
Cilt: 22
Sayı: 1-3
Sayfa: 712-718
ISSN: 0924-4247
Sınıflandırma :
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