Peak Output Voltage Research Articles

Carbon nanofiber-polyelectrolyte triggered piezoelectric polymer-based hydrophilic nanocomposite for high sensing voltage generation

Flexible electronic devices with flexible sensors have drawn enormous attention due to their wide variety of applications, such as wearable health monitoring devices, bendable touch screens, flexible storage devices, artificial skins, etc. However, the mechanical and electrical performance of devices should be enhanced by new materials design or an innovative device structure to fulfill the requirements for such applications. Here, a poly(vinylidenefluoride) (PVDF) piezoelectric polymer-based hydrophilic nanocomposite (PHNC) sensing membrane using carbon nanofibers (CNF) and poly-acrylamido-methyl-propane-sulfonic acid (PAMPS) polyelectrolyte exhibiting enhanced mechanical and electrical performance is demonstrated. The hydrophilic PAMPS intruded in the PVDF/CNF composition, triggering microstructural changes and facilitating a strong polar β-phase PVDF formation. A dc conductivity of 0.43 S/cm and high electric current density (3.64 μA/cm2) were achieved from PVDF/CNF/PAMPS (80/2/18) PHNC. The piezoelectric performance of the PHNC was investigated for several bending cycles, and it generates the maximum peak output voltage up to 3.65 V under the repeated bending-releasing test procedure. A wearable sensor application is demonstrated by exposing it to different human body movements. During finger motion and elbow movements, the developed PHNC generated piezoelectric maximum peak output voltage up to 3.58 V at a bending angle of 180° for finger motion and 2.2 V for elbow movement. The fabricated PHNC are highly flexible and exhibit outstanding reproducibility and reliability, making them ideal for energy harvesting, the self-powered sensor in wearable electronic devices, electronic skin (e-skin), and soft robotics applications.

An Array of Flag-Type Triboelectric Nanogenerators for Harvesting Wind Energy.

Harvesting wind energy from the ambient environment is a feasible method for powering wireless sensors and wireless transmission equipment. Triboelectric nanogenerators (TENGs) have proven to be a stable and promising technology for harvesting ambient wind energy. This study explores a new method for the performance enhancement and practical application of TENGs. An array of flag-type triboelectric nanogenerators (F-TENGs) for harvesting wind energy is proposed. An F-TENG consists of one piece of polytetrafluoroethylene (PTFE) membrane, which has two carbon-coated polyethylene terephthalate (PET) membranes on either side with their edges sealed. The PTFE was pre-ground to increase the initial charge on the surface and to enhance the effective contact area by improving the surface roughness, thus achieving a significant improvement in the output performance. The vertical and horizontal arrays of F-TENGs significantly improved the power output performance. The optimal power output performance was achieved when the vertical parallel distance was approximately 4D/15 (see the main text for the meaning of D), and the horizontal parallel distance was approximately 2D. We found that the peak output voltage and current of a single flag-type TENG of constant size were increased by 255% and 344%, respectively, reaching values of 64 V and 8 μA, respectively.

Stretchable, Adhesive, Self-Healable, and Conductive Hydrogel-Based Deformable Triboelectric Nanogenerator for Energy Harvesting and Human Motion Sensing.

Hydrogels that combine the integrated attributes of being adhesive, self-healable, deformable, and conductive show great promise for next-generation soft robotic/energy/electronic applications. Herein, we reported a dual-network polyacrylamide (PAAM)/poly(acrylic acid) (PAA)/graphene (GR)/poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) (MAGP) conductive hydrogel composed of dual-cross-linked PAAM and PAA as well as PEDOT:PSS and GR as a conducting component that combines these features. A wearable strain sensor is fabricated by sandwiching the MAGP hydrogels between two dielectric carbon nanotubes (CNTs)/poly(dimethylsiloxane) (PDMS) layers, which can be utilized to monitor delicate and vigorous human motion. In addition, the hydrogel-based sensor can act as a deformable triboelectric nanogenerator (D-TENG) for harvesting mechanical energy. The D-TENG demonstrates a peak output voltage and current of 141 V and 0.8 μA, respectively. The D-TENG could easily light 52 yellow-light-emitting diodes (LEDs) simultaneously and demonstrated the capability to power small electronics, such as a hygrometer thermometer. This work provides a potential approach for the development of deformable energy sources and self-powered strain sensors.

Boosting the output of bottom-electrode droplets energy harvester by a branched electrode

Droplets energy harvesters(DEHs) have attracted tremendous attention and shown great potential in harvesting energy from falling water. Current approaches to enhance the device output through adapting a top-electrode in direct contact with the droplets face the drawbacks of fixed droplet-imping-location and inevitable electrode corrosion. Herein, we proposed an easy but effective way to boost the performance of bottom-electrode DEHs through adapting a partial-electrode configuration. It was found that droplets impinging at the boundary between a blank region and the electrode region, instead of at the electrode region, could improve the output peak voltage and current by more than one order of magnitude, up to 30 V. The mechanism is contributed to that water across the boundary bridges the blank and the electrode region for notable inter-region charge transfer, leading to an enhanced electrostatic induction. The induced peak current is proven to be proportional to the changing rate of droplet area on top of the electrode upon initial overlap, and inversely proportional to the thickness of the polymer film in our test range. Based on these findings, DEH with a branched electrode is designed to harvest energy from falling droplets of random positions, as well as energy from turbulent flow of time-variant shapes with an output voltage up to one hundred volts.

Piezoelectric energy harvester with double cantilever beam undergoing coupled bending-torsion vibrations by width-splitting method

We propose piezoelectric energy harvester (PEH) with double-cantilever-beam (DCB) undergoing coupled bending-torsion vibrations by combining width-splitting method and asymmetric mass, in order that more ambient energy could be harvested from environmental vibration with multiple-frequency excitation. The geometrical dimensions are optimized for PEHDCB, when the maximum of output peak voltages Up-max and resonance frequency difference (Δf0) between the first and second modes are chosen as optimization objectives based on orthogonal test method. The energy harvesting efficiency is evaluated by the proportion of half-power bandwidth and quality factor, and the experimental and simulation results are compared to verify reliability. The Up-max1 and Pp-max1 are increased 25.2% and 57.3% for PEHDCB under the multi-frequency excitation, when the split-width method is applied into PEH with single-cantilever-beam (SCB) undergoing coupled bending-torsion vibrations. The deviations of Up-max1 and f0 are at the ranges of 4.9–14.2% and 2.2–2.5% for PEHDCB under the different mass ratios, and the measurement reliability is acceptable considering incomplete clamping, damping and inevitable assembly effects. The energy harvesting efficiency of PEHDCB presented is much higher than that of the conventional PEHSCB from environmental vibration with multiple-frequency excitation.

Numerical simulation of single-event effects in fully-depleted silicon-on-insulator HfO<sub>2</sub>-based ferroelectric field-effect transistor memory cell

Ferroelectric field-effect transistor (FeFET) memory is currently a popular non-volatile memory. It has many advantages such as nonvolatility, better scalability, energy-efficient switching with non-destructive read-out and anti-radiation. To promote the application of FeFET in radiation environments, the single-event transient effect in HfO<sub>2</sub>-based fully-depleted silicon-on-insulator (FDSOI) FeFET memory cell is studied by technology computer aided design (TCAD) numerical simulation. The effects of different incident positions and angles of heavy ions and the drain bias voltage on the characteristics of the memory cell are analyzed. The results show that the corresponding polarization state in the HfO<sub>2</sub> ferroelectric layer will not reverse regardless of the change for the incident position of heavy ions, but the transient change of the output voltage for the memory cell will be affected. The most sensitive area is close to the drain-body junction area. Moreover, with the decrease of the ion incidence angle, the peak of output voltage for the memory cell increases. And the effect of the incident angle change is more obvious when reading data is “0” rather than “1”. The peak of output voltage for the memory cell is modulated by the drain bias voltage, and the modulation effect is more obvious when reading data is “1” rather than “0”. The above findings provide theoretical basis and guidance for the anti-single event design of the FDSOI FeFET memory cell.

Analysis and experiment of an airflow energy harvester based on diamagnetic levitation

This paper proposes an energy harvesting structure that can effectively generate electrical power. Diamagnetic levitation mechanism is utilized, with a floating magnet rotor levitated between two pyrolytic graphite plates just using a lifting magnet and airflow. The magnet rotor could be stably suspended under joint action of magnetic forces and diamagnetic forces, being driven to rotate by airflow. Three magnet rotors, with 1.5 mm, 3 mm and 4.5 mm thickness respectively, were adopted in the study so as to investigate the influence of structural parameters of the magnet rotor on the performance of the harvester. Simulation and experiment were carried out for the three magnet rotors. Among the tree magnet rotors, the 1.5 mm-thick one has the best output performance, with the lowest dynamic stability. Therefore, the energy harvester is to find tradeoff between output characteristics and dynamics. In this work, it was discovered that the peak output voltage of the energy harvester increased with the square of flowrate. As the flowrate increased to 3000 sccm, the 1.5 mm-thick rotor was rotating at a speed of 19729 rpm under standard temperature and pressure, with 1.255 V output voltage and 49 mW power. The diamagnetic levitation structure is expected to be applied to sensing, energy harvesting and air bearing under actuation of airflow due to its advantages of low friction, high rotation speed and large levitation space.

Energy harvesting performance of an EDLC power generator based on pure water and glycerol mixture: analytical modeling and experimental validation

A liquid droplet oscillating between two plane electrodes was visualized, and the electrical power generation based on the reverse-electrowetting-on-dielectric (REWOD) phenomenon was measured. For the upper plate, a hydrophobic surface treated by PTFE was used, and the lower plate was tested using the hydrophilic surface properties of ITO glass. To analyze the dynamic behavior of an oscillating liquid bridge, a modeling study was carried out using the phase field method based on the finite element method. The dynamic contact angle of the oscillating liquid bridge was modeled based on advancing and receding contact angles. The variable interfacial areas between the liquid and solid surfaces were calculated and agreed well with the experimental results within a 10% error band. Furthermore, experimental and analytical studies were carried out to examine the REWOD energy harvesting characteristics of the glycerol-water mixtures in various concentrations. As a result, the peak voltage output was obtained at a specific concentration of the glycerol mixture, and the power density of the oscillating liquid bridge at this point was up to 2.23 times higher than that of pure water.

Side-Illuminated Photoconductive Semiconductor Switch Based on High Purity Semi-Insulating 4H-SiC

High purity semi-insulating (HPSI) 4H-silicon carbide (SiC) was used to fabricate lateral and vertical photoconductive semiconductor switches (PCSSs). The lateral PCSSs were illuminated from the frontside (fPCSS) or the backside (bPCSS). The side-illuminated vertical PCSS (vPCSS) was designed to increase the light-matter interaction volume. A 532-nm pulsed laser with adjustable energy was utilized to excite the PCSSs. The turn-on time was found to be highly dependent on the optical illumination energy, and the full-width at half-maximum of the PCSSs output waveforms was related to the peak output voltage. The output electrical pulse from the vPCSS exhibited a shorter turn-on time and a larger pulsewidth than the two types of lateral PCSSs. The vPCSS outperformed the fPCSS and bPCSS in terms of minimum <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mathrm{\scriptscriptstyle ON}$ </tex-math></inline-formula> -state resistance and output pulse amplitude under the same optical illumination energy. The vPCSS, which utilizes a large effective contact area to collect photogenerated carriers, also had higher photon absorption efficiency by arranging the optical path at a right angle to the carrier transport. The vPCSS exhibited a minimum <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mathrm{\scriptscriptstyle ON}$ </tex-math></inline-formula> -state resistance of 0.34 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\Omega $ </tex-math></inline-formula> at optical illumination energy of 8 mJ.

An explicit solution for the design of a target-frequency-customized, piezoelectric-defect-introduced phononic crystal for elastic wave energy harvesting

This paper proposes an explicit solution for the design of a target-frequency-customized, one-dimensional phononic crystal (PNC) with a defect for piezoelectric energy harvesting under longitudinal waves. Due to the innate narrow bandwidth nature of the defect modes of a PNC at the target frequency, there is a great need to generate an electromechanically coupled defect band of a piezoelectric-defect-introduced PNC. This work considers the transfer matrix method which has been widely used in analytical approaches. The need for defect bands to be included in a bandgap inspires the use of a quarter-wave stack as a unit cell to match the bandgap's central frequency with the target frequency. In band structure analysis, considering that the electromechanically coupled defect band corresponds to a set of real wavenumbers despite being within the bandgap, several possible solutions for the piezoelectric defect's length are derived in an explicit fashion. Since switching from a short- to an open-circuit condition causes defect bands to slightly increase due to piezoelectric effects, an explicit solution that reflects the piezoelectric defect's electrical characteristics is finally proposed. Finite-element-based numerical validation studies are conducted to study two aspects, specifically parametric studies (i.e., the natural numbers in the solution to the piezoelectric defect's length, the supercell sizes, and the defect locations) and supporting studies (i.e., the electrical boundary conditions and unit cell designs). At the target frequency, it is demonstrated that the proposed PNC design actualizes the formation of one defect band and the representation of the peak output voltage.

Energy harvesting from wind by an axially retractable bracket-shaped piezoelectric vibrator excited by magnetic force

Harvesting energy from the wind to replace the conventional electrochemical batteries has gained considerable interest. An axially retractable bracket-shaped piezoelectric vibrator excited by magnetic force is proposed to provide a practical solution to the low reliability and narrow bandwidth of the traditional turbine-based piezoelectric wind energy harvesters (PWEHs). To prove the feasibility and explore the influence of the structure parameters of the bracket-shaped vibrator on the power generation performance, the theoretical analysis, simulation, fabrication and experimental tests were performed for the turbine-based PWEH. The results showed that the bending angle, the excitation distance of magnets, the number ratio of exciting magnets and the stiffness ratio of springs brought significant effects on the performance in terms of electric output, cut-in wind speed, cut-out wind speed, and wind speed bandwidth. The maximal peak output voltage was significantly affected by the magnet spacing and the number of exciting magnets. The cut-in wind speed decreased with the increasing magnet spacing and meanwhile it was hardly influenced by both the number ratio of magnets and the stiffness ratio of springs. The cut-out wind speed was also decreased with the increase of magnet spacing and there was an optimal number ratio of magnets and an optimal stiffness ratio of spring to maximize the cut-out wind speed. Besides, there was an optimal excitation distance, number ratio of magnets and stiffness ratio of springs respectively, where the wind speed could reach the maximum value. A maximum power of 2.13 mW could be achieved with the magnet spacing of 7 mm, the magnet number ratio of 0.83 and stiffness ratio of 10.08, respectively. It was expected this study could provide a useful reference for improving the reliability and experimental adaptability of PWEHs.

Schottky DC generators with considerable enhanced power output and energy conversion efficiency based on polypyrrole-TiO2 nanocomposite

Conversion of small mechanical energy into electricity using a Schottky diode is an emerging technology showing great potential in energy harvesting, sensors, and power generation because of the unique direct current (DC) output characteristic. However, it is still challenging to develop Schottky DC generators with ample power output and energy conversion efficiency. Herein, we, for the first time, demonstrate a novel approach to improve the electrical outputs of a Schottky DC generator using a nanocomposite from polypyrrole and titanium dioxide (TiO2) nanoparticles, a high dielectric material, and aluminum metal. The nanocomposite device showed a current output of 572.70 μA (working area 1.33 cm2) and peak voltage output of 0.84 V with a power density of 0.62 W m−2 and an energy conversion efficiency of as high as 27.29%, which 48 times higher in current outputs, 167 times higher in power density, and 20 times higher in conversion efficiency in comparison to the device made of pure polypyrrole and aluminum metal. We further showed that the presence of TiO2 nanoparticles considerably increased the dielectric constant but slightly reduced the dielectric loss of the polypyrrole composite, leading to a reduction in the Schottky junction internal resistance. However, the Schottky barrier height was little changed, the effect mechanism of which is significantly different from the Schottky DC devices made of polypyrrole-containing graphene oxides and nano carbons. These novel understandings may form a novel concept for the development of high-performance Schottky DC generators.

Analysis of ocean wave power plant buoy system at Kelong

The potential of sea waves, located precisely in the Berakit area, can be used as electrical energy on a small scale. Kelong is a floating house situated on the coast, which anglers (fishermen) use to catch fish. In the Bintan area, there are two types of kelong, namely floating kelong and cacak (permanent) kelong. Floating kelong, as the name implies, is a kelong that can be moved anywhere. During the fish season, the kelong are offered to the middle of the sea, but if the west wind season or not during the fish season, the kelong will be brought ashore. On the other hand, kelong cacak are usually not far from the beach or coast and cannot be moved and operated at night by using a lamp to catch cuttlefish or anchovies. This research was conducted on Kelong Cacak and Floating Kelong (pontoon) located in Berakit, Disability Telok Sebong, Kabubapen Bintan. The power generation system was built using the buoy method. Based on the research results, the wave power plant can be driven by sea waves with an average height of 6 cm and produces a voltage and continuously the voltage is not always stable. The maximum peak output voltage is up to 15 Volt DC; after knowing the test results, the power plant can supply as a charger for the battery in the kelong cacak of 0.8839 Volt DC with an average battery voltage of 10.052 Volt DC and total voltage charging is 0.37 Volt DC, with average battery voltage 11.4902 Volt DC on Floating Kelong (Pontoon).

3D-printed flexible, multilayered ceramic-polymer composite grid with integrated structural-self-sensing function

Piezo-polymer is widely used for pressure sensors or electromechanical transducers; and normally, it is simply designed and prepared into thin film as a force-sensing element integrated in smart structures or robots. In this paper, we report a flexible, three-dimensional multilayer composite grid complex structure containing inside electrode layers prepared totally based on direct-writing 3D printing method. The composite material is composed of a polydimethylsiloxane (PDMS) elastomer matrix and 0.55Pb (Ni1/3Nb2/3) O3-0.135PbZrO3- 0.315PbTiO3 (PNN-PZT) piezoelectric ceramic particles coated with Ag and multi-walled carbon nanotubes (1 wt% of the Ag@PNN-PZT ceramic powders). The 3D-printed composite grid exhibits both large piezoelectric effect (with an effect piezoelectric coefficient (d33) of 21 pC/N) and qualified mechanical performances, such as a large failure tensile strain of 150% and tensile stress of 2.2 MPa. Under a dynamic compression stress of 0.125 MPa at 3.5 Hz, a 3D-printed 7-layer composite grid (550 μm in thickness) with internal electrode layers inside could produce output voltage peak of 3 V accompanying with a peak current of 0.7 μA. In comparison with a single layer composite grid, its peak output current shows a 7-time increase, although its peak output voltage keeps unchanged under the same compression stress. This work shows that the 3D-printed multilayer composite grid exhibits the integrated structural-self-sensing function, which will bring great benefits to future artificial muscle in robots and other flexible intelligent structures.

High-performance triboelectric nanogenerator based on carbon nanomaterials functionalized polyacrylonitrile nanofibers

Triboelectric nanogenerators (TENGs) are one of the most promising energy sources for self-powered electronic devices in the near future. Improving the dielectrics with high tribo-potential is a primary requirement to increase the output performance of TENGs. In this study, spring supported TENGs consisting of polyvinylpyrrolidone/ethyl-cellulose (PVP/EC) nanofibers and various carbon-doped polyacrylonitrile (PAN) nanofibers as positive and negative dielectric layers, respectively, were fabricated. According to the experimental results, reduced graphene oxide (rGO) and carbon nanotube (CNT) which were grafted to PAN matrix, both increased surface charge density and enhanced the output voltage of the TENGs. On the other hand, carbon black (CB) reduced the tribo-potential of PAN as a negative dielectric layer. As the best result, a 40 × 40 mm2 TENG constructed of PVP/EC and 3 wt% CNT doped PAN nanofibers demonstrates high triboelectric characteristics with a charge capacity of 260 nC (under 0.022 μF capacitive load), a maximum peak output voltage of 960 V (under a 70 MΩ load resistance), and a maximum peak power density of 14.6 W/m2 (under a 14.6 MΩ load resistance). In other words, the addition of 3 wt% CNT to PAN increased the charge amount by 136%, and the maximum peak power density by 125%. This work presents an effective way to take advantage of the coupling effect of carbon additive and nanofiber structure to significantly enhance the output performance of TENGs.

Enhanced output performance of tetraethyl orthosilicate and graphene nanoplates-decorated nanofiber-based triboelectric nanogenerators

Smart and self-powered electronic devices are becoming more popular but require more power. Therefore, we need to improve the output performance of triboelectric nanogenerators (TENGs) to supply enough power the electronic devices. This paper proposed an effective method to obtain high-output performance TENGs composed of polyvinyl butyral nanofibers decorated with additives paired with polyacrylonitrile (PAN) nanofiber. Polyvinyl butyral decorated with graphene nanoplatelets (GNPs) and tetraethyl orthosilicate (TEOS) significantly improves the output voltage, current, and power density of TENGs. A 5 × 5 cm2 TENG consisting of PVBT3 and PAN nanofiber has high output performance with a maximum peak output voltage of 810 V, a charge capacity of 198 nC, a maximum output current of 263 µA, and a maximum power density of 20 W/m2, which is almost six times as high as that of a PVB TENG (3.48 W/m2). The results show that the synergistic effect of TEOS and GNP and the structural property of TEOS and GNP-doped nanofiber tribomaterials fabricated via electrospinning improve the triboelectric output performance of TENGs. The nanofiber-based TENG is an eco- and user-friendly TENG with superior output performance. Therefore, it brings a new perspective to tribomaterials and is a promising solution for intelligent and self-powered electronic devices.

Solid-State Pulsed Power Generator Based on Blumlein PFN Using Saturable Pulse Transformer

A solid-state pulsed power generator has been developed. It is based on Blumlein pulse forming network (PFN) combined with saturable pulse transformer (SPT). The primary circuit is switched by a switching unit consisting of three MOS-gated thyristors connected in parallel. The SPT functions both as a transformer to increase the voltage and as a closing switch for the secondary circuit. The PFN on the secondary side is charged by the transformer and switched by the SPT so that a pulsed output is generated on a matched load. In the demonstration experiment using one module, an output with peak voltage of ~10.4 kV and pulsewidth of ~160 ns was obtained on a resistive load of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$52~\Omega $ </tex-math></inline-formula> . Furthermore, three identical modules, sharing a common primary circuit, have been connected in series to demonstrate voltage adding, where a peak output voltage of ~30 kV was obtained on a load of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$156~\Omega $ </tex-math></inline-formula> with energy efficiency of ~54 %. This pulsed power generator has been tested at repetition rate of 20 kHz in burst mode.

Evaluation of Electromechanical Properties and Conversion Efficiency of Piezoelectric Nanocomposites with Carbon-Fiber-Reinforced Polymer Electrodes for Stress Sensing and Energy Harvesting.

Wireless sensor networks are the future development direction for realizing an Internet of Things society and have been applied in bridges, buildings, spacecraft, and other areas. Nevertheless, with application expansion, the requirements for material performance also increase. Although the development of carbon-fiber-reinforced polymer (CFRP) to achieve these functions is challenging, it has attracted attention because of its excellent performance. This study combined the CFRP electrode with epoxy resin containing potassium sodium niobate piezoelectric nanoparticles and successfully polarized the composite sample. Furthermore, a three-point bending method was applied to compare the bending behavior of the samples. The peak output voltage produced by the maximum bending stress of 98.4 MPa was estimated to be 0.51 mV. Additionally, a conversion efficiency of 0.01546% was obtained. The results showed that the piezoelectric resin with CFRPs as the electrode exhibited stress self-inductance characteristics. This study is expected to be applied in manufacturing self-sensing piezoelectric resin/CFRP composite materials, paving the way for developing stable and efficient self-sensing structures and applications.

Design and Fabrication of Thermocouple Sensors Based on a Ceramic Curved Alumina Substrate

A platinum-platinum/rhodium thick-film thermocouple sensor based on an alumina curved-surface ceramic substrate was designed. The thermoelectric components were prepared by screen printing, which is simple, rapid, and low cost; additionally, screen-printed films have uniform thickness. We investigated the as-fabricated morphologies of Pt and Pt/Rh films using scanning electron microscopy (SEM) and X-ray diffraction (XRD). The results show that the thermocouple film prepared via this process was reasonably stable at high temperatures. We then repeated the test at 1300 °C and then at 1500 °C for 10 h to determine its thermal limits. After testing at 30-1300 °C thrice, the fabricated thermocouple showed excellent consistency and reusability, with a maximum output voltage of 11.733 mV and a Seebeck coefficient of 9.110 μV/ <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">°</sup> C. Upon testing the thermocouple at 1500 °C for 10 hours, the peak voltage output was 12.821 mV. Therefore, we concluded that the sensor could be used for temperature monitoring in hostile environments such as measurement of turbine blade surface temperature for aeroengines.

High-PSRR Low-dropout Regulator with Fast Transient Response Time and Low Output Peak Voltage

This study proposes the feed-forward ripple cancellation (FFRC) technique to low drop-out (LDO) regulator. By adding load tracking impedance to the gate of pass transistor, it is possible to secure stability with a 100-nF capacitor having low ESR and be obtained less than 35 ㎱ response time. In all frequency bands, a power supply rejection ratio (PSRR) less than -70 ㏈ is obtained when the load current is 10 ㎃. The circuit is implemented in 65-㎚ CMOS process.