Power Sensor Research Articles

A 53-µA-Quiescent 400-mA Load Demultiplexer Based CMOS Multi-Voltage Domain Low Dropout Regulator for RF Energy Harvester

A low-power capacitorless demultiplexer-based multi-voltage domain low-dropout regulator (MVD-LDO) with 180 nm CMOS technology is proposed in this work. The MVD-LDO has a 1.5 V supply voltage headroom and regulates an output from four voltage domains ranging from 0.8 V to 1.4 V, with a high current efficiency of 99.98% with quiescent current of 53 µA with the aid of an integrated low-power demultiplexer controller which consumes only 68.85 pW. The fabricated chip has an area of 0.149 mm2 and can deliver up to 400 mA of current. The MVD-LDO's line and load regulations are 1.85 mV/V and 0.0003 mV/mA for the low-output voltage domain and 3.53 mV/V and 0.079 mV/mA for the high-output voltage domain. The LDO consumes only 174.5 µW in standby mode, making it suitable for integrating with an RF energy harvester chip to power sensor nodes.

Compatibility assessment of TEGs arrangement coupled with DC/DC converter to harvest electricity from low-temperature heat sources

Expanding intelligent control systems based on the Internet of Things (IoT) requires powering sensors, actuators, and wireless data transfer, which may be located off-grid or difficult to access. Energy harvesting from industrial excess heat by thermoelectric generators (TEGs) can help to overcome challenges ahead. A fully integrated TEG system, however, remains an obstacle to the effective conversion of heat into electricity for IoT applications. The purpose of this paper is to investigate experimentally the electrical arrangement of TEGs and the design of a DC-DC boost converter in order to optimize the harvesting of electrical power from low-temperature sources of heat in TEG systems. The results of this study provide a guide for selecting a suitable arrangement in a system with several TEGs as well as for the design of matched DC-DC converters with desired electrical generators and consumers. This study shows the impact of specialized arrangement of TEGs in a power generation system to optimize the output power of a DC-DC converter. Accordingly, the most suitable electrical combination of four TEG modules among series, parallel-series, and parallel connections is discussed with heat source temperatures lower than 55 °C, between 55 and 75 °C, and higher than 75 °C. Based on the results of the studied TEG system, it is determined that using inductors and capacitors lower than 0.33 µH and 0.47 µF, respectively in the converter’s circuit decreases the output power dramatically, and delays the startup point to higher heat source temperatures.

Broadband microwave detection using electron spins in a hybrid diamond-magnet sensor chip

Quantum sensing has developed into a main branch of quantum science and technology. It aims at measuring physical quantities with high resolution, sensitivity, and dynamic range. Electron spins in diamond are powerful magnetic field sensors, but their sensitivity in the microwave regime is limited to a narrow band around their resonance frequency. Here, we realize broadband microwave detection using spins in diamond interfaced with a thin-film magnet. A pump field locally converts target microwave signals to the sensor-spin frequency via the non-linear spin-wave dynamics of the magnet. Two complementary conversion protocols enable sensing and high-fidelity spin control over a gigahertz bandwidth, allowing characterization of the spin-wave band at multiple gigahertz above the sensor-spin frequency. The pump-tunable, hybrid diamond-magnet sensor chip opens the way for spin-based gigahertz material characterizations at small magnetic bias fields.

Innovative Technology for Self‐Powered Sensors: Triboelectric Nanogenerators

AbstractInternet of Things and wearable technology's quick development have opened up a vast market for sensor systems. However, typical sensors' external power supplies' short lifespan and expensive maintenance restrict them from being used more widely. Triboelectric nanogenerators (TENGs), a recently created mechanical energy harvesting and self‐powered sensing device, show enormous promise to get over these restrictions. TENG can be used not only to power sensors instead of conventional chemical batteries but also be utilized to actualize sensing by taking advantage of the unique characteristics of the friction layer itself. Triboelectric nanogenerators efficiently provide crucial infrastructure for a new generation of sensing devices that gather data using several self‐powered sensors in abundance. The recent progress in the development of TENGs applied in the sensor field is reviewed. First, the working mechanisms of solid‐solid TENG and solid–liquid TENG are introduced. Subsequently, the development of TENG‐based sensing systems and their application progress in self‐powered temperature sensors, self‐powered pressure sensors, self‐powered humidity sensors, self‐powered atmosphere sensors, self‐powered wireless sensors, interface wetting status monitoring, solution property monitoring, and friction condition monitoring are highlighted. Finally, current challenges and open opportunities are discussed.

Ultra-low frequency multidirectional harvester for wind turbines

In this paper we propose, and demonstrate through a prototype, a completely novel device able to harvest mechanical energy from the multidirectional vibrations in a wind turbine, and convert it into electrical, to power autonomous sensors. The application is very challenging since vibrations are of ultra-low frequency, well below 1 Hz, with accelerations of tenths of cm/s2 (0.01 g), and the device must capture energy from the movement in any direction. According to our experiments, the device is capable to generate average powers around the milliwatt in the operation conditions of a wind turbine, which are enough for some very-low power sensor nodes, or at least to considerably extend the life-time of batteries. The device is based on the principle of moving (inertial) masses comprised of magnets in Hallbach arrays interacting with coils, and can work for movements on any direction of a plane. To the best of our knowledge, this is the first device specifically proposed for wind turbines and one of the few that work in such low frequencies, and capture energy from movements on any direction on a plane. Only three harvesters proposed in the literature, intended for distinct applications, can work at such low frequencies, and our device exhibits a better efficiency. Though comparisons with harvesters working in different contexts and, even using different conversion principles, is not completely fair, we make in this paper a comparison to the closest ones, resorting to two different figures of merit.

Technology update on patent and development trend of power over fiber: a critical review and future prospects

Conventional electricity distribution using copper wires is well established due to its high efficiency. However, recent research and development on power-over-fiber (PoF) has proposed optical fiber as an alternative to copper wire as the transmission medium for electricity distribution. The research and development on PoF technology have gained significant momentum over the past decade due to its advantage over copper cables in providing electrical isolation and reducing space in remote sites. The technological advances in laser diodes, fiber optic cable fabrications, and semiconductor manufacturing contribute to developing an efficient PoF system, making them more commercially viable. This paper reviews various PoF systems that imply different arrangements of high-power lasers, fiber optic cables, and photovoltaic power converters. The PoF systems are made available for various applications such as in-home applications, smart power management, and powering sensors with bidirectional communications. The comparison of the PoF composition, commercialized PoF systems, and patented PoF systems are also comprehensively discussed. Finally, the challenges in implementing PoF systems are highlighted, as well as future prospects for research and applications. The information reviewed in this paper aims to provide a roadmap for developing a future PoF system with improved power conversion efficiency.

Self-image correction for low-cost imaging optic

With the advent of computing power and higher resolution CMOS sensor, imaging camera for mobile phone application has become very common in consumer portable product such as mobile phone, tablet or even wearable devices and head mount devices . Higher resolution image sensor, on the other hand, will suffer chromatic aberration (CA) where the colour channel appears shifted. Better lens design with more lens elements may be required. However, this will add more cost and manufacturing challenges. Many studies and methods have been proposed for CA correction through post image processing and those methods required calibration or post image process before correction factor can be applied. In this paper, we propose a new algorithm that will pre-defined the CA correction factor through lens design simulation.

Self-powered and wireless physiological monitoring system with integrated power supply and sensors

With the increase in people’s concern for personal health, the demand for convenient health monitoring electronics has grown noticeably. Wearable physiological sensors with multi-functionality and continuous power supply are constructed through system-level integration and delicate circuit design for energy management and low-power sensing. Energy harvested from body motion and solar or domestic lighting has great potential in powering wearable electronics, eliminating the need of batteries or plug-in power sources. Triboelectric nanogenerators readily fabricated with digital ink-jet printing display a high-power output of 30.96 mW/cm2 after integration with a flexible thin-film solar cell, which ensures unremitting work of the sensors. The self-powered physiological monitoring system can continuously monitor and wirelessly transmit the electrocardiogram, blood pressure, temperature, and motion parameters of the human in real-time without the need for an external power source, providing the wearer with a reliable monitoring means.

Investigation of properties of Ta-doped Ga2O3 films prepared with seed layers

Ga2O3 is a promising ultra-wide bandgap semiconductor as a feasible candidate for power electronics, photodetectors, and sensors. Controlling electrical properties through doping is the key to its application in semiconductor devices. In this work, Ta-doped Ga2O3 films were prepared by radio frequency (RF) magnetron sputtering with seed layers. Effects of the thickness of seed layers on the microstructure, morphology, optical and electrical properties of Ta-doped Ga2O3 films were investigated. The fabricated Ta-doped Ga2O3 films exhibited polycrystalline structure with uniform and smooth surface and high optical transmittance (＞80 %) in the visible light region. The results showed that seed layers with appropriate thickness (∼20 nm) is beneficial to the improvement of crystalline quality and electrical properties of Ta-doped Ga2O3 films.

A hybrid wind energy harvester based on a double-rotor reverse synergy mechanism for high-speed railway

With the growing expansion of high-speed railway, the power supply have become increasingly crucial. This research proposes a HWEH to power sensors and small electrical devices along the railroad. The four primary components of the HWEH: the parallel piezoelectric module, the electromagnetic synergy module, and the electric energy storage module. The HWEH uses the a double-rotor reverse synergy mechanism to achieve reverse rotation under wind drive. A conductive slip ring is incorporated. Increasing the relative speed of the disks furnished with magnets and coils improves the electromagnetic module's energy harvesting efficiency. The speed of the magnet disk and coil disk connected with the slip ring are increased. The power storage module converts the generated alternating current into direct current, which is then stored in the supercapacitor and used to power the railway monitoring sensor. The performance of the system is tested through simulation and experimentation. Compared with a single rotor, the efficiency of HWEH is improved by 34%. When the wind speed is 9 m/s, the output power of the HWEH is 394 mW. According to the findings of experiments, the HWEH has a high energy generation performance and can power sensors and other small electrical equipment along the railroad.

Role of MXenes in advancing soft robotics.

MXenes with their unique electronic, optical, chemical, and mechanical properties have shown great promise in soft robotics. MXene-based soft actuators have been designed to display ultrafast actuations and recovery speeds as well as angle-independent structural colors in response to vapor. Several studies have developed soft actuators by combining MXenes with other materials to mimic the movement of natural organisms. Thus, MXene-based soft actuators have the potential to revolutionize the field of soft robotics and flexible electronics (e.g., wearable devices and artificial muscles). MXene-based artificial muscles have been explored for use in kinetic soft robotics as actuators in microsystems requiring exceptional compliance. MXene-based sensors and actuators have already been developed for human-like sensors and photodetection. However, there are still challenges that need to be addressed in such applications, such as the design of stretchable and compliant robotic skins with a high-level functional integration for soft robotics. The integration of various devices, such as power sources, sensors, and actuators, into soft robotics is another crucial challenge. Despite the excellent stretchability and tensile strength of MXene-based composites, there is a vital need to develop their mechanical and electrochemical features and grant them multi-functionalities. Herein, recent developments pertaining to the applications of MXenes and their composites in soft robotics are discussed with a focus on the important challenges and future perspectives.

Study and Mechanism of Magnetocardiography (MCG) Device and its Comparison to Electrocardiography (ECG) in Heart Diseases

Background: Magnetocardiography device is the best tool for diagnosing heart diseases in a more accurate way. This device is related to the superconductors and squid. In Afghanistan there has been no research conducted about it. Therefore, the aim of this study is to explore the structure, activity and information related to the application of magnetocardiography theoretically. Materials and Methods: The research design for this study is reflective in nature, utilizing a review research approach. This involves examining existing literature, reports, and empirical studies published in peer review journals about the structure and mechanism of the magnetocardiography device and its comparison with electrocardiography. The obtained information was summarized, compared the previous and current articles, and the results obtained are placed here. Findings: Today, in the medical field, magnetocardiography is an advanced device, which diagnoses diseases in shortage of time accurately and quickly. In addition, the magnetocardiography device used to diagnose heart diseases has very few negative effects on human body against other devices. Conclusion: Calculation of this magnetic field from the superconducting quantum interference device (SQUID) is the only powerful magnetic sensor to measure human biological magnetic activity so far. A comparison of conventional sensor arrangements (MCG/ECG) and optimized sensor arrangements were made by determining the slope of individual values, and its application for heart diseases very effectively. MCG is used in the imaging of patients for whom the time required is much less than the time of ECG measurement.

Synthesis of a novel hydrazone-based compound applied as a fluorescence turn-on chemosensor for iron(iii) and a colorimetric sensor for copper(ii) with antimicrobial, DFT and molecular docking studies.

Hydrazone-hydrazide-based linkers perform a crucial role in environmental as well as biological fields. Such linkers are employed to detect exact metal ions at a minute level; hence, numerous probes are available. Even though thiophene-based molecules have a unique position in the medicinal arena, only very few chemosensors are reported based on such a moiety. In this current work, a novel hydrazide-hydrazone-based fluorogenic molecule 5-bromo-2-hydroxy-N'-[(1E)-1-(thiophen-2-yl)ethylidene]benzohydrazide (L) has been successfully designed and synthesized. The sensing studies of L demonstrated a ratio metric as well as turn-on-enhanced fluorescence and colorimetric response toward Fe3+ and Cu2+ ions, respectively and it was observed to be insensitive toward various metal ions. The Job plots revealed that the binding stoichiometry of L and metal ions is 2 : 1. In addition, density functional theory (DFT) results strongly suggested that L can be used as a powerful colorimetric sensor for the detection of Cu2+ ions. In vitro antimicrobial activities of L were evaluated by disk diffusion and results revealed good antibacterial activities against E. coli. Further, molecular docking was executed with DNA gyrase (PDB ID: 1KZN) of E. coli and the calculated interaction energy value was found to be -7.7 kcal mol-1. Finally, molecular docking, fluorescence, colorimetry and the HOMO-LUMO energy gap of the compound can provide new insights into developing drugs and detecting metals in biomolecules.

Blockchain and 1D-CNN based IoTs for securing and classifying of PCG sound signal data

The Internet of Things (IoTs) has accelerated with the introduction of powerful biomedical sensors, telemedicine services and population ageing are concerns that can be solved by smart healthcare systems. However, the security of medical signal data that collected from sensors of IoTs technology, while it is being transmitted over public channels has grown to be a serious problem that has limited the adoption of intelligent healthcare systems. This suggests using the technology of blockchain to create a safe and reliable heart sound signal (PCG) that can communicate with wireless body area networks. The security plan offers a totally dependable and safe environment for every data flowing from the back end to front-end. Also in this paper, to classify heart sound signals, we suggested a one-dimensional convolutional neural network (1D-CNN) model. The denoising autoencoder extracted the heart sounds' deep features as an input feature of 1D-CNN. To extract the detailed characteristics from the PCG signals, a Data Denoising Auto Encoder (DDAE) was used instead of the standard MFCC, the suggested model shows significant improvement. The system's benefits include a less difficult encryption algorithm and a more capable and effective blockchain-based data transfer and storage system.

A Novel Circularly Polarized Annular Slotted Multiband Rectenna for Low Power Sensor Applications

A Novel Circularly Polarized Annular Slotted Multiband Rectenna for Low Power Sensor Applications

Theoretical and Experimental Investigations of an Integrated Microwave Power, Frequency, and Phase Detector for X-Band Applications

In this article, we present an integrated microwave power, frequency, and phase detector by GaAs monolithic microwave integrated circuits technology. The novelty of the reported detector is carefully designed by cascading a micromachined six-port coupler, a power divider, three power combiners, and four thermoelectric power sensors to realize microwave power, phase, and frequency detection. Compared with previous study, the reported microwave integrated detector has a more compact design and high-power-handling capacity. The advantage of the proposed technique is that the three parameters (power, frequency, and phase) of microwave signals are directly measured via the output of the thermovoltage. This makes the integrated microwave detection system more suitable for systems with complex requirements, such as radar systems. The experimental results demonstrate that the output thermovoltage and incident microwave power exhibit good linearity over a dynamic range of 0.1–1000 mW. Also, the measured sensitivities are 22.9, 27.2, and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$33.7~\mu \text{V}$ </tex-math></inline-formula> /mW at 8, 10, and 12 GHz, respectively. A new method based on phase comparison is proposed for frequency detection. Also, the measured sensitivity is <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$9.42~^{\circ }$ </tex-math></inline-formula> /GHz over <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${X}$ </tex-math></inline-formula> -band. By introducing the reference signal, the function of phase detection is achieved based on the principle of vector synthesis over a dynamic range of 0°–360°. Also, the measured sensitivity is better than 98.38 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu \text{V}$ </tex-math></inline-formula> /° at 500 mW. Furthermore, an integrated detection model is also proposed based on the microwave network analysis. The experimental results agree well with the proposed model. The results would be beneficial to improve future microwave integrated detector designs.

An In-depth Analysis of Uneven Clustering Techniques in Wireless Sensor Networks

The low-cost and convenient feature of Wireless Sensor Networks (WSNs) has made them popular in many sectors over the last decade. The WSNs are now widely used as a result of recent advancements in low-power communication and being energy-efficient. The WSNs typically use batteries to power sensor nodes. The finite stored energy in batteries and the hassle of battery replacement have led to a critical focus on energy efficiency for WSNs. Clustering and data aggregation are the most efficient methods to address the energy concerns of WSNs. This paper comprehensively reviews several uneven clustering methods and compares the various uneven clustering algorithms. The methods are described in terms of their goals, attributes, categories, advantages and disadvantages. Probabilistic clustering is used when there is a need of simplicity and speed. As a result, this study compared all these types of protocols based on their clustering properties, CHs properties, and on the type of clustering process; and current research gap effective techniques are also addressed.

Strain effect on the field-effect sensing property of Si wires.

Silicon-based field effect transistor (FET) sensors with high sensitivity are emerging as powerful sensors for detecting chemical/biological species. Strain engineering has been demonstrated as an effective means to improve the performance of Si-based devices. However, the strain effect on the field-effect sensing property of silicon materials has not been studied yet. Here, we investigate the strain effect on the field-effect sensing property of silicon wires by taking humidity sensing as an example. The humidity sensitivity of FET sensors based on silicon wires increases with increasing tensile strain but decreases with increasing compressive strain. The sensitivity is very responsive to strain with an enhancement factor of 67 for tensile strain. Theoretical analysis shows that the sensitivity variation under different strains is mainly attributed to the change in adsorption energy between silicon wires and water molecules. This work indicates that strain engineering can be an effective route to modulate the field-effect sensing property of Si wires for constructing highly sensitive Si-based FET sensors.

Joint Virtual Machine Selection and Computation Resource Allocation in Mobile Edge Computing

Mobile edge computing (MEC) is considered as an effective technology to enhance the storage and computation capability of smart power sensors (SPSs) in smart grid networks. The MEC server is composed of multiple virtual machines (VMs) with powerful computation capability, and each VM can process multiple tasks independently, which cannot be ignored during the task computation period. In this work, we aim to minimize the energy consumption of SPSs subject to the task offloading delay by jointly optimizing the VM selection and computation resource allocation. Considering the formulated problem is nonconvex, we first utilize the linearization method to transform it into a convex optimization problem. And then, by using the branch and bound method, we propose the joint VM selection and computation resource allocation (JVMSRA) algorithm. Considering the complexity of the JVMSRA algorithm is high, we decompose the primal problem into two subproblems and solve them by utilizing the ant colony method and CVX package, respectively. Based on the solutions of the two subproblems, the resource allocation‐based ant colony (RAAC) algorithm is proposed. Simulation results show that the proposed RAAC algorithm and JVMSRA algorithm decrease by 6% and 8.8% on average compared with the benchmark algorithm, respectively, when the computation resources of each VM increase from 1 to 3GHz.

Design and Analysis of Charge Plasma-Based Vertical-Nanowire Tunnel FET for Biosensor

In the semiconductor industry, nanoscale devices have better ability to provide for biomolecules detection, but they face various problems during fabrication process, such as high doping concentration, random dopant fluctuation (RDF), higher production cost, low electrostatic control. To overcome these problems, charge plasma (CP) technique has been introduced by the formation of hafnium material at drain side and platinum material at source side with appropriate work-function. The proposed work charge plasma-based vertical-nanowire tunnel FET (CP-VNWTFET) has been designed and analyzed for biosensor application using different dielectric constant and gate underlap method by creating a cavity area under the gate metal. The sensitivity ([Formula: see text]) of biosensor is calculated in terms of change in drain-current ([Formula: see text]) and transconductance ([Formula: see text]) by immobilizing the biomolecules such as Urease, Keratin, Streptavidin, ChOX, Zein, Gluten using gate underlap and dielectric modulation technique. The performance parameters like subthreshold slope (SS), off-current ([Formula: see text]), on-current ([Formula: see text]), on/off current ratio ([Formula: see text]) of the CP-VNWTFET have also been observed while varying the neutral and charged biomolecules at various biased conditions. The device is simulated by using Silvaco ATLAS simulator. The proposed device has been found to be suitable for low power sensor design application.