- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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Selective Functionalization of High-Resolution Cu2O Nanopatterns via Galvanic Replacement for Highly Enhanced Gas Sensing Performance
摘要： Recently, high-resolution patterned metal oxide semiconductors (MOS) have gained considerable attention for enhanced gas sensing performance due to their polycrystalline nature, ultrasmall grain size (~5 nm), patternable properties, and high surface-to-volume ratio. Herein, we significantly enhanced the sensing performance of that patterned MOS by galvanic replacement, which allows for selective functionalization on ultrathin Cu2O nanopatterns. Based on the reduction potential energy difference between the base channel material (Cu2O) and the decorated metal ion (Pt2+), Pt could be selectively and precisely decorated onto the desired area of the Cu2O nanochannel array. Overall, the Pt-decorated Cu2O exhibited 11-fold higher NO2 (100 ppm) sensing sensitivity as compared to the non-decorated sensing channel, the while the channel device with excessive Pt doping showed complete loss of sensing properties.
关键词： galvanic replacement,chemical sensitization,p-type metal oxide,gas sensor,high-resolution,nanopattern
更新于2025-09-23 15:23:52
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Fundamental Study on Blood Pressure Measurement by FBG Sensor
摘要： In recent years, the demands for vital sign measurement system have been increasing, such as home health care for elderly people, or self-health management for healthy people. In this study, we aimed at the development of a non-invasive wearable device to measure vital sign. We use a Fiber Bragg Grating (FBG) sensor as pulse wave sensor. A FBG sensor is the optical ?ber. Therefore, a FBG sensor has a lot of features. Its characteristics are suitable for the measurement of vital signs at all times. We ?x FBG sensors to di?erent two points of the body surface and acquired pulse wave. We calculated the systolic blood pressure by using Pulse Transit Time (PTT) which is arrival time lag of pulse wave. We have con?rmed the validity of the principle of systolic blood pressure measurement by FBG sensors.
关键词： wearable,blood pressure measurement,FBG sensor
更新于2025-09-23 15:23:52
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Device noise reduction for silicon nanowire field-effect-transistor based sensors by using a Schottky junction gate
摘要： The sensitivity of metal-oxide-semiconductor field-effect transistor (MOSFET) based nanoscale sensors is ultimately limited by noise induced by carrier trapping/detrapping processes at the gate oxide/semiconductor interfaces. We have designed a Schottky junction gated silicon nanowire field-effect transistor (SiNW-SJGFET) sensor, where the Schottky junction replaces the noisy oxide/semiconductor interface. Our sensor exhibits significantly reduced device noise, 2.1×10-9 V2μm2/Hz at 1 Hz, compared to reference devices with the oxide/semiconductor interface operated at both inversion and depletion modes. Further improvement can be anticipated by wrapping the nanowire by such a Schottky junction thereby eliminating all oxide/semiconductor interfaces. Hence, a combination of the low-noise SiNW-SJGFET device with a sensing surface of the Nernstian response limit holds promises for future high signal-to-noise ratio sensor applications.
关键词： Noise reduction,field-effect transistor,ion sensor,low frequency noise,schottky junction gate,silicon nanowire
更新于2025-09-23 15:23:52
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Multi-target joint detection, tracking and classification based on random finite set for aerospace applications
摘要： Multi-target detection, tracking and classification are important problems in aerospace applications, such as reconnaissance, airborne and spaceborne sensing. These problems are correlated but are difficult to be solved simultaneously, especially for systems with multiple sensors. This paper summarized the existing work for multi-target joint detection, tracking and classification based on labeled random finite set. Furthermore, a new algorithm is proposed for multi-sensor multi-target joint detection, tracking and classification problem. A conditional multi-sensor multi-target state estimator is derived, and the optimal solution is then obtained based on the minimum Bayes risk criterion. The numerical simulations are performed, and the results are shown to be more accurate than that of the approximate solutions based on the unlabeled random finite set. It is observed that the labeled random finite set theory provides a good foundation for a joint solution for multi-target detection, tracking and classification.
关键词： Multiple targets,Tracking and classification,Labeled RFS,Generalized bayesian risk,Sensor registration,Joint detection
更新于2025-09-23 15:23:52
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Highly sensitive strain sensor based on a novel Mach–Zehnder mode interferometer with TCF-PCF-TCF structure
摘要： We have demonstrated a high-sensitivity strain sensor based on a novel photonic crystal fiber (PCF) interferometer by means of splicing two sections of thin core fibers (TCF) with a piece of PCF between two single mode fibers (SMFs). The proposed MZI has exhibited an excellent fringe visibility as high as 21 dB in air. Particularly, the measurement range was up to 4 m ε and a strain sensitivity of ?1.89 pm/με was achieved. It was found that the strain sensitivity of the MZI was weekly dependent on the PCF length. The measured sensitivities of the MZI with 25 mm, 30 mm and 35 mm PCF at ～1590 nm were ?1.83 pm/με, ?1.85 pm/με and ?1.77 pm/με, respectively. Moreover, the temperature characteristics of the sensor were also investigated. Additionally, the sensor has advantages of simplicity of fabrication, low cost, compact size as well as large strain measurement range.
关键词： Strain sensor,Mach–Zehnder interferometer (MZI),Photonic crystal fiber (PCF),Thin core fiber (TCF)
更新于2025-09-23 15:23:52
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Highly Responsive PEG/Gold Nanoparticle Thin Film Humidity Sensor via Inkjet Printing Technology
摘要： In this study, a highly responsive humidity sensor is developed by printing gold nanoparticles (GNP) grafted with a hygroscopic polymer. These GNPs are inkjet printed to form a uniform thin film over an interdigitated electrode with controllable thickness by adjusting the printing parameters. The resistance of the printed GNP thin film decreases significantly upon exposure to water vapor and exhibits a semi-log relationship with relative humidity (RH). The sensor can detect RH variations from 1.8% to 95% with large resistance changes up to 4 order of magnitude with no hysteresis and small temperature dependence. In addition, with a thin thickness, the sensor can reach absorption equilibrium quickly with response and recovery times of ≤1.2 and ≤3 seconds, respectively. The fast response to humidity changes also allows the GNP thin film sensor to distinguish signals from intermittent humidification/dehumidification cycles with a frequency up to 2.5 Hz. The printed sensors on flexible substrates show little sensitivity to bending deformation and can be embedded in a mask for human respiratory detection. In summary, this study demonstrates the feasibility of applying printing technology for the fabrication of thin film humidity sensors, and the developed methodology can be further applied to fabricate many other types of nanoparticle based sensor devices.
关键词： inkjet printing,respiratory monitoring,Humidity sensor,gold nanoparticle,poly(ethylene glycol)
更新于2025-09-23 15:23:52
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Room temperature ammonia gas sensor based on Au/ graphene nanoribbon
摘要： Graphene nanoribbon (GNR) is a strip and 1D shape of graphene which can be an appropriate candidate for gas sensing application due to its significant electrical and chemical characteristic. In this study, graphene nanoribbon is employed for the NH3 detection process. The chemical approach is applied for unzipping MWCNTs by using KMnO4, as an oxidative material in graphene oxide nanoribbon synthesis process. The gold comb-like electrodes as a sensor structure is produced by standard deposition and photolithography methods. The quality of the synthesized GNRs is investigated by different analyses such as SEM, XRD, Raman Spectroscopy, and FTIR. In addition to GNR sensor preparation, AuGNR sensor is fabricated by gold sputtering deposition on a GNR sensor surface. The experimental results for sensors indicate that AuGNR and GNR sensors could be the appropriate choices for NH3 detection. The experimental tests for AuGNR and GNR sensors are performed for different NH3 concentration at room temperature which showed 34 % and 12.1% response for 25 ppm NH3 respectively. Furthermore, in 25 ppm for the AuGNR sensor, the sensor shows 224 s for response time, and 178 s for recovery time for a graphene-based sensor. All the tests are carried out at room temperature.
关键词： GNRs,gas sensor,AuGNR,NH3 detection
更新于2025-09-23 15:23:52
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Sol-gel assisted nano-structured SnO<sub>2</sub> sensor for low concentration ammonia detection at room temperature
摘要： Sol-gel assisted nano-structured SnO2 sensor for low concentration ammonia detection at room temperature. Upon exposure to 500 ppb and 1 ppm of NH3, sensor manifests appreciable response ~ 28 % and ~ 31.5 %, respectively. High response of the sensor at RT is attributed due to porous nanograins (with average particle size ~ 50 nm) based SnO2 thin film layer. Nanograins structure is obtained due to addition of glycerine in the sol solution, which also leads to porosity enhancement of the sensing layer. Good reproducibility and appreciable immunity to drift behavior are other attributes of the fabricated device. High response and good selectivity towards ammonia are observed with very fast response and recovery time at RT, for extreme low concentrations level ~ 55 % RH for concentration range 500 ppb-500 ppm. X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM) and scanning electron microscopy (SEM) results are used to study the structural, chemical composition, topography and morphological characteristics of the prepared SnO2 thin film, respectively.
关键词： Sol-gel,Room temperature,Ammonia sensor,Metal oxides,% Response,Nanostructured
更新于2025-09-23 15:23:52
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New modeling method for UV sensor photoelectrical parameters extraction
摘要： In this work, we have developed a new modeling tools based on physical, mathematical and numerical models for the analysis of UV-photodetectors based on ZnO NRs/PPV-C6 hybrid heterojunctions. The photoelectrical equivalent circuit parameters are the series resistance (Rs), the shunt resistance (Rp), the reverse current density (J0), the ideality factor (n) and the photocurrent density (Jph). A combined physical-mathematical-numerical approach based on the modified Schockley model, the Lambert W function and the optimized method of the Root Mean Square error (RMSE) was applied to analyze the different devices performances. The results demonstrate that the incorporation of PPV-C6 polymer to the ZnO NRs structure leads to significant amelioration in the interface and increase of both the Jph and responsivity with a decrease of the Rs. This kind of hybrid heterojunction based UV light sensor is promising for future low cost and high performance optoelectronic devices development.
关键词： Photodetectors,Hybrid heterojunction,UV sensor,Modeling,Photoelectrical properties
更新于2025-09-23 15:23:52
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Ammonia sensing properties of two-dimensional tin disulphide/tin oxides (SnS2/SnO2-x) mixed phases
摘要： 2D-SnS2 flakes were synthesized via a wet chemical route and deposited as a thin film onto the Pt-interdigitated contacts of a ceramic substrate with aim to fabricate a conductometric sensor. The 2D-SnS2 sensing film was then annealed "in situ" under controlled conditions at different temperatures up to 400 °C. The morphological, microstructural and electrical properties of the sensing film, before and after the thermal treatment, were characterized by "in situ" techniques. SEM analysis has shown that the 2D flake morphology was maintained after thermal treatments, whereas Raman and EDX analysis have highlighted the partial/total modification of the SnS2 phase towards the SnO2. As a consequence of the formation of 2D-SnS2/SnO2-x mixed phases, a dramatic change of the electrical properties of the sensing film has been also observed. Conductometric gas sensors based on hybrid SnS2-SnO2-x nanoflakes were then obtained by simple self-annealing treatments of 2D-SnS2 film directly on the sensor substrate. The fabricated sensors were tested toward ammonia (NH3) as target gas. Results evidence that increasing the annealing temperature of the 2D-SnS2 sensitive film, the electrical resistance of the sensing layer decreases while the response towards ammonia increases, showing the maximum at an annealing treatment of 250 °C. This behaviour was explained on the basis of the morphological, microstructural and electrical modifications observed, highlighting the role of 2D-SnS2/SnO2-x mixed phases in determining the sensing properties towards ammonia.
关键词： Heterostructure,Gas sensor,NH3,2D-SnS2 flakes,Ammonia
更新于2025-09-23 15:23:52