Moussab/ORKG-training-evaluation-set huggingface dataset:
Research field: Engineering
Title: High-isolation CPW MEMS shunt switches-part 1: modeling 
Abstract: This paper, the first of two parts, presents an electromagnetic model for membrane microelectromechanical systems (MEMS) shunt switches for microwave/millimeter-wave applications. The up-state capacitance can be accurately modeled using three-dimensional static solvers, and full-wave solvers are used to predict the current distribution and inductance of the switch. The loss in the up-state position is equivalent to the coplanar waveguide line loss and is 0.01-0.02 dB at 10-30 GHz for a 2-/spl mu/m-thick Au MEMS shunt switch. It is seen that the capacitance, inductance, and series resistance can be accurately extracted from DC-40 GHz S-parameter measurements. It is also shown that dramatic increase in the down-state isolation (20/sup +/ dB) can be achieved with the choice of the correct LC series resonant frequency of the switch. In part 2 of this paper, the equivalent capacitor-inductor-resistor model is used in the design of tuned high isolation switches at 10 and 30 GHz.
Extracted statement — Study Area : Microelectromechanical Systems (MEMS)
Research field: Engineering
Title: RF MEMS Switches With Enhanced Power-Handling Capabilities
Abstract: This paper reports on the experimental and theoretical characterization of RF microelectromechanical systems (MEMS) switches for high-power applications. First, we investigate the problem of self-actuation due to high RF power and we demonstrate switches that do not self-actuate or catastrophically fail with a measured RF power of up to 5.5 W. Second, the problem of switch stiction to the down state as a function of the applied RF power is also theoretically and experimentally studied. Finally, a novel switch design with a top electrode is introduced and its advantages related to RF power-handling capabilities are presented. By applying this technology, we demonstrate hot-switching measurements with a maximum power of 0.8 W. Our results, backed by theory and measurements, illustrate that careful design can significantly improve the power-handling capabilities of RF MEMS switches.
Extracted statement — Study Area : Microelectromechanical Systems (MEMS)
Research field: Engineering
Title: Fabrication of low pull-in voltage RF MEMS switches on glass substrate in recessed CPW configuration for V-band application
Abstract: A new technique for the fabrication of radio frequency (RF) microelectromechanical systems (MEMS) shunt switches in recessed coplaner waveguide (CPW) configuration on glass substrates is presented. Membranes with low spring constant are used for reducing the pull-in voltage. A layer of silicon dioxide is deposited on glass wafer and is used to form the recess, which partially defines the gap between the membrane and signal line. Positive photoresist S1813 is used as a sacrificial layer and gold as the membrane material. The membranes are released with the help of Pirhana solution and finally rinsed in low surface tension liquid to avoid stiction during release. Switches with 500 µm long two-meander membranes show very high isolation of greater than 40 dB at their resonant frequency of 61 GHz and pull-in voltage less than 15 V, while switches with 700 µm long six-strip membranes show isolation greater than 30 dB at the frequency of 65 GHz and pull-in voltage less than 10 V. Both types of switches show insertion loss less than 0.65 dB up to 65 GHz.
Extracted statement — Study Area : Microelectromechanical Systems (MEMS)
Research field: Engineering
Title: RF MEMS Shunt Capacitive Switches Using AlN Compared to Si3N4 Dielectric
Abstract: RF microelectromechanical systems (MEMS) capacitive switches for two different dielectrics, aluminum nitride (AlN) and silicon nitride (Si3N4), are presented. The switches have been characterized and compared in terms of DC and RF performance (5-40 GHz). Switches based on AlN have higher down-state capacitance for similar dielectric thicknesses and provide better isolation and smaller insertion losses compared to Si3N4 switches. Experiments were carried out on RF MEMS switches with stiffening bars to prevent membrane deformation due to residual stress and with different spring and meander-type anchor designs. For a ~300-nm dielectric thickness, an air gap of 2.3 μm and identical spring-type designs, the AlN switches systematically show an improvement in the isolation by more than -12 dB (-35.8 dB versus -23.7 dB) and a better insertion loss (-0.68 dB versus -0.90 dB) at 40 GHz compared to Si3N4. DC measurements show small leakage current densities for both dielectrics (<;10-8 A/cm2 at 1 MV/cm). However, the resulting leakage current for AlN devices is ten times higher than for Si3N4 when applying a larger electric field. The fabricated switches were also stressed by applying different voltages in air and vacuum, and dielectric charging effects were investigated. AlN switches eliminate the residual or injected charge faster than the Si3N4 devices do.
Extracted statement — Study Area : Microelectromechanical Systems (MEMS)
Research field: Engineering
Title: Effects of surface roughness on electromagnetic characteristics of capacitive switches
Abstract: This paper studies the effect of surface roughness on up-state and down-state capacitances of microelectromechanical systems (MEMS) capacitive switches. When the root-mean-square (RMS) roughness is 10 nm, the up-state capacitance is approximately 9% higher than the theoretical value. When the metal bridge is driven down, the normalized contact area between the metal bridge and the surface of the dielectric layer is less than 1% if the RMS roughness is larger than 2 nm. Therefore, the down-state capacitance is actually determined by the non-contact part of the metal bridge. The normalized isolation is only 62% for RMS roughness of 10 nm when the hold-down voltage is 30 V. The analysis also shows that the down-state capacitance and the isolation increase with the hold-down voltage. The normalized isolation increases from 58% to 65% when the hold-down voltage increases from 10 V to 60 V for RMS roughness of 10 nm.
Extracted statement — Study Area : Microelectromechanical Systems (MEMS)
Research field: Engineering
Title: Quality Inspection of Textile Artificial Textures Using a Neuro-Symbolic Hybrid System Methodology 
Abstract: In the industrial sector there are many processes where the visual inspection is essential, the automation of that processes becomes a necessity to guarantee the quality of several objects. In this paper we propose a methodology for textile quality inspection based on the texture cue of an image. To solve this, we use a Neuro-Symbolic Hybrid System (NSHS) that allow us to combine an artificial neural network and the symbolic representation of the expert knowledge. The artificial neural network uses the CasCor learning algorithm and we use production rules to represent the symbolic knowledge. The features used for inspection has the advantage of being tolerant to rotation and scale changes. We compare the results with those obtained from an automatic computer vision task, and we conclude that results obtained using the proposed methodology are better.
Extracted statement — has methodology: Neuro-symbolic Hybrid System
Research field: Engineering
Title: Enhancement of c-Axis Oriented Aluminum Nitride Films via Low Temperature DC Sputtering
Abstract: In this study, we successfully deposit c-axis oriented aluminum nitride (AlN) piezoelectric films at low temperature (100 °C) via the DC sputtering method with tilt gun. The X-ray diffraction (XRD) observations prove that the deposited films have a c-axis preferred orientation. Effective d33 value of the proposed films is 5.92 pm/V, which is better than most of the reported data using DC sputtering or other processing methods. It is found that the gun placed at 25° helped the films to rearrange at low temperature and c-axis orientation AlN films were successfully grown at 100 °C. This temperature is much lower than the reported growing temperature. It means the piezoelectric films can be deposited at flexible substrate and the photoresist can be stable at this temperature. The cantilever beam type microelectromechanical systems (MEMS) piezoelectric accelerometers are then fabricated based on the proposed AlN films with a lift-off process. The results show that the responsivity of the proposed devices is 8.12 mV/g, and the resonance frequency is 460 Hz, which indicates they can be used for machine tools.
Extracted statement — Device type: Piezoelectric accelerometers
Research field: Engineering
Title: Glucose Biosensor Based on Disposable Activated Carbon Electrodes Modified with Platinum Nanoparticles Electrodeposited on Poly(Azure A)
Abstract: Herein, a novel electrochemical glucose biosensor based on glucose oxidase (GOx) immobilized on a surface containing platinum nanoparticles (PtNPs) electrodeposited on poly(Azure A) (PAA) previously electropolymerized on activated screen-printed carbon electrodes (GOx-PtNPs-PAA-aSPCEs) is reported. The resulting electrochemical biosensor was validated towards glucose oxidation in real samples and further electrochemical measurement associated with the generated H2O2. The electrochemical biosensor showed an excellent sensitivity (42.7 μA mM−1 cm−2), limit of detection (7.6 μM), linear range (20 μM–2.3 mM), and good selectivity towards glucose determination. Furthermore, and most importantly, the detection of glucose was performed at a low potential (0.2 V vs. Ag). The high performance of the electrochemical biosensor was explained through surface exploration using field emission SEM, XPS, and impedance measurements. The electrochemical biosensor was successfully applied to glucose quantification in several real samples (commercial juices and a plant cell culture medium), exhibiting a high accuracy when compared with a classical spectrophotometric method. This electrochemical biosensor can be easily prepared and opens up a good alternative in the development of new sensitive glucose sensors.
Extracted statement — keywords: platinum nanoparticles
Research field: Engineering
Title: Glucose Biosensor Based on Disposable Activated Carbon Electrodes Modified with Platinum Nanoparticles Electrodeposited on Poly(Azure A)
Abstract: Herein, a novel electrochemical glucose biosensor based on glucose oxidase (GOx) immobilized on a surface containing platinum nanoparticles (PtNPs) electrodeposited on poly(Azure A) (PAA) previously electropolymerized on activated screen-printed carbon electrodes (GOx-PtNPs-PAA-aSPCEs) is reported. The resulting electrochemical biosensor was validated towards glucose oxidation in real samples and further electrochemical measurement associated with the generated H2O2. The electrochemical biosensor showed an excellent sensitivity (42.7 μA mM−1 cm−2), limit of detection (7.6 μM), linear range (20 μM–2.3 mM), and good selectivity towards glucose determination. Furthermore, and most importantly, the detection of glucose was performed at a low potential (0.2 V vs. Ag). The high performance of the electrochemical biosensor was explained through surface exploration using field emission SEM, XPS, and impedance measurements. The electrochemical biosensor was successfully applied to glucose quantification in several real samples (commercial juices and a plant cell culture medium), exhibiting a high accuracy when compared with a classical spectrophotometric method. This electrochemical biosensor can be easily prepared and opens up a good alternative in the development of new sensitive glucose sensors.
Extracted statement — keywords: poly(Azure A)
Research field: Engineering
Title: Efficiently Improving the Stability of Inverted Perovskite Solar Cells by Employing Polyethylenimine-Modified Carbon Nanotubes as Electrodes
Abstract: Inverted perovskite solar cells (PSCs) have been becoming more and more attractive, owing to their easy-fabrication and suppressed hysteresis, while the ion diffusion between metallic electrode and perovskite layer limit the long-term stability of devices. In this work, we employed a novel polyethylenimine (PEI) modified cross-stacked superaligned carbon nanotube (CSCNT) film in the inverted planar PSCs configurated FTO/NiO x/methylammonium lead tri-iodide (MAPbI3)/6, 6-phenyl C61-butyric acid methyl ester (PCBM)/CSCNT:PEI. By modifying CSCNT with a certain concentration of PEI (0.5 wt %), suitable energy level alignment and promoted interfacial charge transfer have been achieved, leading to a significant enhancement in the photovoltaic performance. As a result, a champion power conversion efficiency (PCE) of ∼11% was obtained with a Voc of 0.95 V, a Jsc of 18.7 mA cm-2, a FF of 0.61 as well as negligible hysteresis. Moreover, CSCNT:PEI based inverted PSCs show superior durability in comparison to the standard silver based devices, remaining over 85% of the initial PCE after 500 h aging under various conditions, including long-term air exposure, thermal, and humid treatment. This work opens up a new avenue of facile modified carbon electrodes for highly stable and hysteresis suppressed PSCs.
Extracted statement — keywords: Power conversion efficiency
Research field: Engineering
Title: Fabrication of Efficient Low-Bandgap Perovskite Solar Cells by Combining Formamidinium Tin Iodide with Methylammonium Lead Iodide
Abstract: Mixed tin (Sn)-lead (Pb) perovskites with high Sn content exhibit low bandgaps suitable for fabricating the bottom cell of perovskite-based tandem solar cells. In this work, we report on the fabrication of efficient mixed Sn-Pb perovskite solar cells using precursors combining formamidinium tin iodide (FASnI3) and methylammonium lead iodide (MAPbI3). The best-performing cell fabricated using a (FASnI3)0.6(MAPbI3)0.4 absorber with an absorption edge of ∼1.2 eV achieved a power conversion efficiency (PCE) of 15.08 (15.00)% with an open-circuit voltage of 0.795 (0.799) V, a short-circuit current density of 26.86(26.82) mA/cm(2), and a fill factor of 70.6(70.0)% when measured under forward (reverse) voltage scan. The average PCE of 50 cells we have fabricated is 14.39 ± 0.33%, indicating good reproducibility.
Extracted statement — keywords: Power Conversion Efficiency
Research field: Engineering
Title: Flexible capacitive pressure sensor with sensitivity and linear measuring range enhanced based on porous composite of carbon conductive paste and polydimethylsiloxane
Abstract: In recent years, the development of electronic skin and smart wearable body sensors has put forward high requirements for flexible pressure sensors with high sensitivity and large linear measuring range. However it turns out to be difficult to increase both of them simultaneously. In this paper, a flexible capacitive pressure sensor based on porous carbon conductive paste-PDMS composite is reported, the sensitivity and the linear measuring range of which were developed using multiple methods including adjusting the stiffness of the dielectric layer material, fabricating micro-structure and increasing dielectric permittivity of dielectric layer. The capacitive pressure sensor reported here has a relatively high sensitivity of 1.1 kPa-1 and a large linear measuring range of 10 kPa, making the product of the sensitivity and linear measuring range is 11, which is higher than that of the most reported capacitive pressure sensor to our best knowledge. The sensor has a detection of limit of 4 Pa, response time of 60 ms and great stability. Some potential applications of the sensor were demonstrated such as arterial pulse wave measuring and breathe measuring, which shows a promising candidate for wearable biomedical devices. In addition, a pressure sensor array based on the material was also fabricated and it could identify objects in the shape of different letters clearly, which shows a promising application in the future electronic skins.
Extracted statement — keywords: Pressure sensor
Research field: Engineering
Title: Highly Sensitive, Transparent, and Durable Pressure Sensors Based on Sea-Urchin Shaped Metal Nanoparticles
Abstract: Highly sensitive, transparent, and durable pressure sensors are fabricated using sea-urchin-shaped metal nanoparticles and insulating polyurethane elastomer. The pressure sensors exhibit outstanding sensitivity (2.46 kPa-1 ), superior optical transmittance (84.8% at 550 nm), fast response/relaxation time (30 ms), and excellent operational durability. In addition, the pressure sensors successfully detect minute movements of human muscles.
Extracted statement — keywords: pressure sensors
Research field: Engineering
Title: Hybrid Perovskite Films by a New Variant of Pulsed Excimer Laser Deposition: A Room-Temperature Dry Process
Abstract: A new variant of the classic pulsed laser deposition (PLD) process is introduced as a room-temperature dry process for the growth and stoichiometry control of hybrid perovskite films through the use of nonstoichiometric single target ablation and off-axis growth. Mixed halide hybrid perovskite films nominally represented by CH3NH3PbI3–xAx (A = Cl or F) are also grown and are shown to reveal interesting trends in the optical properties and photoresponse. Growth of good quality lead-free CH3NH3SnI3 films is also demonstrated, and the corresponding optical properties are presented. Finally, perovskite solar cells fabricated at room temperature (which makes the process adaptable to flexible substrates) are shown to yield a conversion efficiency of about 7.7%.
Extracted statement — keywords: Pulsed Laser Deposition
Research field: Engineering
Title: Ultrasensitive refractive index sensor based on enhanced Vernier effect through cascaded fiber core-offset pairs
Abstract: An ultrasensitive refractive index (RI) sensor based on enhanced Vernier effect is proposed, which consists of two cascaded fiber core-offset pairs. One pair functions as a Mach-Zehnder interferometer (MZI), the other with larger core offset as a low-finesse Fabry-Perot interferometer (FPI). In traditional Vernier-effect based sensors, an interferometer insensitive to environment change is used as sensing reference. Here in the proposed sensor, interference fringes of the MZI and the FPI shift to opposite directions as ambient RI varies, and to the same direction as surrounding temperature changes. Thus, the envelope of superimposed fringe manifests enhanced Vernier effect for RI sensing while reduced Vernier effect for temperature change. As a result, an ultra-high RI sensitivity of -87261.06 nm/RIU is obtained near the RI of 1.33 with good linearity, while the temperature sensitivity is as low as 204.7 pm/ °C. The proposed structure is robust and of low cost. Furthermore, the proposed scheme of enhanced Vernier effect provides a new perspective and idea in other sensing field. © 2020 Optical Society of America under the terms of the OSA Open Access Publishing Agreement
Extracted statement — keywords: refractive index
Research field: Engineering
Title: A zipper RF MEMS tunable capacitor with interdigitated RF and actuation electrodes
Abstract: This paper presents a new RF MEMS tunable capacitor based on the zipper principle and with interdigitated RF and actuation electrodes. The electrode configuration prevents dielectric charging under high actuation voltages. It also increases the capacitance ratio and the tunable analog range. The effect of the residual stress on the capacitance tunability is also investigated. Two devices with different interdigital RF and actuation electrodes are fabricated on an alumina substrate and result in a capacitance ratio around 3.0 (Cmin = 70?90 fF, Cmax = 240?270 fF) and with a Q > 100 at 3 GHz. This design can be used in wideband tunable filters and matching networks.
Extracted statement — keywords: RF MEMS
Research field: Engineering
Title: RF MEMS Shunt Capacitive Switches Using AlN Compared to Si3N4 Dielectric
Abstract: RF microelectromechanical systems (MEMS) capacitive switches for two different dielectrics, aluminum nitride (AlN) and silicon nitride (Si3N4), are presented. The switches have been characterized and compared in terms of DC and RF performance (5-40 GHz). Switches based on AlN have higher down-state capacitance for similar dielectric thicknesses and provide better isolation and smaller insertion losses compared to Si3N4 switches. Experiments were carried out on RF MEMS switches with stiffening bars to prevent membrane deformation due to residual stress and with different spring and meander-type anchor designs. For a ~300-nm dielectric thickness, an air gap of 2.3 μm and identical spring-type designs, the AlN switches systematically show an improvement in the isolation by more than -12 dB (-35.8 dB versus -23.7 dB) and a better insertion loss (-0.68 dB versus -0.90 dB) at 40 GHz compared to Si3N4. DC measurements show small leakage current densities for both dielectrics (<;10-8 A/cm2 at 1 MV/cm). However, the resulting leakage current for AlN devices is ten times higher than for Si3N4 when applying a larger electric field. The fabricated switches were also stressed by applying different voltages in air and vacuum, and dielectric charging effects were investigated. AlN switches eliminate the residual or injected charge faster than the Si3N4 devices do.
Extracted statement — keywords: RF MEMS
Research field: Engineering
Title: RF MEMS Switches With Enhanced Power-Handling Capabilities
Abstract: This paper reports on the experimental and theoretical characterization of RF microelectromechanical systems (MEMS) switches for high-power applications. First, we investigate the problem of self-actuation due to high RF power and we demonstrate switches that do not self-actuate or catastrophically fail with a measured RF power of up to 5.5 W. Second, the problem of switch stiction to the down state as a function of the applied RF power is also theoretically and experimentally studied. Finally, a novel switch design with a top electrode is introduced and its advantages related to RF power-handling capabilities are presented. By applying this technology, we demonstrate hot-switching measurements with a maximum power of 0.8 W. Our results, backed by theory and measurements, illustrate that careful design can significantly improve the power-handling capabilities of RF MEMS switches.
Extracted statement — keywords: RF MEMS switches
Research field: Engineering
Title: Sensitivity-Enhanced Fiber Temperature Sensor Based on Vernier Effect and Dual In-Line Mach–Zehnder Interferometers
Abstract: A highly sensitive fiber temperature sensor based on in-line Mach-Zehnder interferometers (MZIs) and Vernier effect was proposed and experimentally demonstrated. The MZI was fabricated by splicing a section of hollow core fiber between two pieces of multimode fiber. The temperature sensitivity obtained by extracting envelope dip shift of the superimposed spectrum reaches to 528.5 pm/°C in the range of 0 °C–100 °C, which is 17.5 times as high as that without enhanced by the Vernier effect. The experimental sensitivity amplification factor is close to the theoretical predication (18.3 times).The proposed sensitivity enhancement system employs parallel connecting to implement the Vernier effect, which possesses the advantages of easy fabrication and high flexibility.
Extracted statement — keywords: sensitivity enhancement