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[IEEE 2018 14th International Conference on Advanced Trends in Radioelecrtronics, Telecommunications and Computer Engineering (TCSET) - Lviv-Slavske (2018.2.20-2018.2.24)] 2018 14th International Conference on Advanced Trends in Radioelecrtronics, Telecommunications and Computer Engineering (TCSET) - Formation of the image of investigated biological objects with small contrast in a scanning TV microscope
摘要： It is analyzed ways and methods of contrast improvements of biological objects images, which are created by television optical microscope. Advantages of TV scanning microscope usage for biological objects images formations are reviewed. Methods of research stages which allow to improve microscope parameters are shown in this paper.
关键词： image contrast,biological object,microscope calibration,microscope sensitivity
更新于2025-09-09 09:28:46
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Resonator-Inspired Metamaterial Sensor: Design and Experimental Validation for Measuring Thickness of Multi-Layered Structures
摘要： A digit 8-shaped resonator inspired metamaterial is proposed herein for sensor applications. The resonator is surrounded by a ground frame and excited by a microstrip feedline. The measurement of the sensor can be performed using common laboratory facilities in lieu of using the waveguide, as the resonator, ground frame, and feedline are all on the same microstrip. To achieve metamaterial properties, more than one unit cell is usually utilized, whereas, in this work, a single cell was used to achieve the metamaterial characteristics. The properties of the metamaterial were investigated to find the relationship between the simulation and measurements. The proposed metamaterial sensor shows considerable sensitivity in sensor application. For the sensor application, FR4 and Rogers RO4350 materials were used as the over-layer. The sensor can measure dielectric thickness with a sensitivity of 625 MHz/mm, 468 MHz/mm, and 354 MHz/mm for the single over-layer, double over-layers, and multiple over-layers, respectively. The proposed prototype can be utilized in several applications where metamaterial characteristics are required.
关键词： metamaterial sensor,sensitivity,resonator,thickness
更新于2025-09-09 09:28:46
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An Accurate Analysis of Phase Noise in CMOS Ring Oscillators
摘要： We present an accurate analysis of phase noise in ring oscillators, where each stage in the ring is a CMOS inverter loaded by a capacitance. Closed-form phase noise expressions are obtained in both 1/f 2 and 1/f 3 offset frequency regions, displaying an excellent agreement with numerical simulations using either ideal Verilog-A MOS models (allowing theoretical predictions to be tested with exactly the same assumptions under which they were derived), or commercial BSIM4 MOS models.
关键词： Phase noise,impulse sensitivity function (ISF),ring oscillators
更新于2025-09-09 09:28:46
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Sensitivity enhancement of SPR optical biosensor based on Graphene–MoS2 structure with nanocomposite layer
摘要： The optical plasmonic biosensors are an important research item in the field of bio-photonics. The graphene-molybdenum disulfide (MoS2) based hybrid structures are very useful in designing and fabrication of the high sensitive biosensors. In this paper, we designed hetero-structured Air/MoS2/Nanocomposite/MoS2/Graphene as an optical biosensor with high sensitivity. The proposed configuration for this Surface Plasmon Resonance (SPR) biosensor is Otto configuration. Herein, the enhancement sensitivity of this proposed SPR biosensor is investigated in different arrangement of layers. The influence of the refractive index of the coupling prism, the thickness of the nanocomposite layer, the constituent components of the nanocomposite layer and the number of the MoS2 layer is investigated and the optimal values is calculated for the biosensor with maximum sensitivity. The maximum sensitivity ～200°/RIU is achieved with six layers of MoS2 layer and a nanocomposite layer containing the gold nanoparticles and TiO2 as host dielectric.
关键词： Sensitivity,Biosensor,Nanocomposite,Graphene,Surface plasmon resonance,Molybdenum disulfide
更新于2025-09-09 09:28:46
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Programmable Flow Rate Scanner for Evaluating Detector Sensitivity Regime
摘要： In order to expedite characterization of on-line detection systems, we have developed a flow rate scanner comprising a pump, an inexpensive single-board computer, and an associated Python program. The program controls the pump, triggers the detector, acquires raw data, filters/smooths the data, calculates the first derivative of the temporal signal trend, and determines the sensitivity regime threshold in real time. The slope of the curve relating the detector response with the sample flow rate is used to determine the sensitivity regime for a given analyte and a given detector. The key part of the data analysis is on-the-fly calculation of the first derivatives using a fourth-order polynomial fit to the raw data by the Savitzky-Golay algorithm. The device has been tested by determining the flow rate profiles for an ultraviolet absorption detector and a mass spectrometer operated with electrospray ionization, atmospheric pressure chemical ionization, and a dual ion source. The sensitivity regime thresholds for various test analytes have been determined automatically and robustly in time as short as a few minutes.
关键词： prototype,mass spectrometry,flow rate,sensitivity,optimization,automation
更新于2025-09-09 09:28:46
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Defected graphene as ammonia sensor: Theoretical Insight
摘要： Defects are often symbolised as deformity in material that deteriorate its performance. However in nanoscale regime, defects lead to generate a useful and novel material for device applications. In the present report, the vacancy defects i.e. single vacancy and double vacancy defects (with different symmetry) on graphene sheet have been analysed to understand the electronic as well as transport properties using density functional theory and NEGF approach. Conductance, current-voltage and sensitivity analysis, these defected graphene sheet have been examined for gas sensing application particularly for ammonia gas. The study observes that a single vacancy defected graphene is a good candidate for ammonia molecule sensing, in comparison to double vacancy.
关键词： DFT,Sensitivity,Ammonia,Graphene,Defects,Conductance
更新于2025-09-09 09:28:46
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Improved pH Sensitivity and Reliability for Extended Gate Field-Effect Transistor Sensors Using High- <i>k</i> Sensing Membranes
摘要： In this study, we fabricated extended-gate (EG) ?eld-effect transistor (FET) pH sensors with dual-gate (DG) structures, using a range of dielectric sensing membranes (SiO2, Si3N4, HfO2 and Ta2O5) to vary their sensitivity. The fabricated EGFETs consisted of a silicon-on-insulator (SOI)-based metal-oxide semiconductor ?eld-effect transistor (MOSFET) transducer and an EG sensor. We ampli?ed the sensitivity of the device far beyond the Nernst limit (59 mV/pH), which is the theoretical maximum of conventional ion-selective FET (ISFET) sensing, by applying capacitive coupling. Among the evaluated dielectric sensing membranes, we obtained the highest sensitivity (478 mV/pH), low hysteresis (100.2 mV) and drift rate (24.6 mV/h) from the pH sensor with a Ta2O5 membrane. Hence, we expect DG FET con?gurations using Ta2O5 ?lms as EG sensing membranes to be useful for high performance biosensor applications, as they satisfy the requirements for sensitivity, stability and reliability.
关键词： Ion-Sensitive Field-Effect Transistor,Sensitivity,High-k Sensing Membrane,Dual-Gate Field-Effect Transistor,pH Sensor,Capacitive Coupling
更新于2025-09-09 09:28:46
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Efficient Modified Bimetallic Alloy Nanoparticles Porous Silicon Gas Sensors for CO Gas Detection Process
摘要： The influence of embedding Au, Pd monometallic and Au-Pd bimetallic nanoparticles on porous silicon-based gas sensor was investigated. Porous silicon layer P-si was prepared by photo electrochemical etching (PECE) with the laser wavelength of about 635 nm and 25 mW/cm2 laser power density. AuNPs/P-si, PdNPs/P-si and Au-PdNPs/P-si hetrostructures were prepared by ion reduction process, this made by dipping fresh P-si in the salt solution contain HAuCl4, PdCl2 and mixing solutions at ratio 1:1 for about (1.2, 5 and 2 min), respectively. Au NPs/P-si, Pd NPs/P-si and Au-Pd NPs/P-si were investigated by scanning electron microscopy (SEM), FTIR analysis, X-ray diffraction (XRD) and energy dispersive X-ray analysis (EDS). Efficient gas sensing process was recorded for modified porous silicon P-si gas sensor with smallest bimetallic Au-Pd nanoparticles size. Considerable improvement in sensitivity and temporal response were obtained for modified bimetallic alloy nanoparticles porous silicon compared with bare P-si and monometallic nanoparticles gas sensors due to the high specific surface area.
关键词： Sensitivity,Ion reduction process,Monometallic,Photo Electrochemical Etching (PECE),Bimetallic,CO gas
更新于2025-09-09 09:28:46
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Organic field effect transistors (OFETs) in environmental sensing and health monitoring: A review
摘要： Organic field effect transistors (OFETs) have been the focus of sensing application research over the last two decades. In comparison to their inorganic counterparts, OFETs have multiple advantages, such as low-cost manufacturing, large area coverage, flexibility and readily tunable electronic material properties. To date, various organic semiconductors (OSCs), both polymers and small molecules, have been extensively researched for the purpose of developing the active channel layers in OFETs, enhancing their sensitivity and selectivity. However, OFET devices still need to be optimized to demonstrate reliable performance at the device level and in sensing applications. This review begins with an introduction of the OFETs with an emphasis on their geometry, materials (OSCs), fabrication process, and data analysis. After this, multiple applications are discussed and the progress regarding sensing elements and precisions is highlighted. In the end, the challenges and possible future directions of OFET arrays in embedded sensing platforms are presented.
关键词： stability,bi-layer,selectivity,biosensor,sensitivity,composites,OFETs,gamma irradiation,VOCs
更新于2025-09-09 09:28:46
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High-sensitivity refractive index sensor with tunable detection range based on dual-core resonance effect in gold-coated photonic crystal fibers
摘要： A high-sensitivity refractive index (RI) sensor with wide tunable detection range based on the dual-core resonance of photonic crystal fibers are presented and studied by the finite element method. A cladding air hole coated with gold film is designed as the microfluidic channel for surface plasmon resonance sensing. The channel filled with liquid analyte acts as a defective core. The directional energy coupling between the fiber core and the defective core which determines the sensing performance is greatly influenced by both the RI of the filled liquid and the structural parameters. Numerical results show that the sensitivity of the sensor increases with the increase of the diameter of the analyte channel, and the RI detection range decreases with the increase of this diameter. So we tune the detection range by adjusting the diameter of the analyte channel to meet specific measurement requirements. As the diameter increases from 1.5 μm to 2.4 μm, the detection range shrinks from 1.45–1.62 to 1.45–1.48, both with the high spectral sensitivity 10 392 nm/RIU and 25 040 nm/RIU, respectively. The sensor with wide adjustable detection range shows great advantages in the field of biochemical, chemistry and environmental detection.
关键词： refractive index sensor,photonic crystal fiber,wide detection range,surface plasmon resonance,high-sensitivity
更新于2025-09-09 09:28:46