Management Circuit Research Articles

A Universal Power Management Strategy Based on Novel Sound‐Driven Triboelectric Nanogenerator and Its Fully Self‐Powered Wireless System Applications

AbstractWith the development of the Internet of Things (IoT), the power supply to trillions of IoT nodes has become a serious challenge. It is of significant importance to propose a rational power management scheme for constructing fully self‐powered systems using triboelectric nanogenerators (TENG). In this study, as inspired by an embroidery hoop, a new type of TENG without the Helmholtz resonant cavity is developed for collecting sound energy, which can generate the Voc and Isc up to 500 V and 124 µA, respectively at a resonance frequency of 170 Hz and sound pressure of 110 dB. Furthermore, the sound‐driven TENG integrated with a specially designed power management circuit derived from the universal power management strategy (PMS) can successfully drive a commercial narrow band‐IoT wireless node, which realizes periodic temperature and humidity data acquisition and transmission. With the same strategy, an electric switch and a temperature and humidity acquisition system based on Bluetooth technology can also be powered by a contact‐separated TENG and a wind‐driven TENG, demonstrating excellent versatility, adaptability, and universality of the PMS. This study provides a novel solution for the application of TENG in the field of low‐frequency IoT in local and wide areas.

Recent Advances towards Ocean Energy Harvesting and Self‐Powered Applications Based on Triboelectric Nanogenerators

AbstractOcean contain abundant clean energies including tidal and wave, but such energies are known for low frequency and large excitation amplitude, posing considerable challenges for high‐efficiency energy conversion. As an emerging technology, triboelectric nanogenerators (TENGs) have been widely used in energy harvesting and novel sensor design due to their high sensitivity and flexible structure. Meanwhile, they show great advantages in the low‐frequency environment (<5 Hz), and display great potential for deployment in remote ocean waters, and construction of large‐scale TENG networks. In this review, firstly, the working principle of TENGs and various configurations developed for the marine environment are introduced, which mainly include solid–solid and solid–liquid interfaces. Then, from the viewpoint of power improvement, authors are most concerned about the modification methods of materials such as surface modification, electron injection, and chemical doping. Meanwhile, improved technologies for energy harvesters in marine environment are discussed in detail, such as improving the hydrophobicity and degradation of materials, studying the self‐healing ability of materials, and designing power management circuits. Finally, the current challenges are summarized, and research trends are given from both short‐term and long‐term perspectives.

A Portable Wireless Urine Detection System With Power-Efficient Electrochemical Readout ASIC and ABTS-CNT Biosensor for UACR Detection.

This work presents a portable wireless urine detection system which consists of an electrochemical readout application specific integrated circuit (ASIC) and a biosensor composed of 2, 2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) and carbon nanotube (ABTS-CNT) for the detection of urine albumin-to-creatinine ratio (UACR). The ASIC includes a potentiostat, a digital circuitry and a power management circuit which can perform electrochemistry techniques with a dual-channel screen-printing carbon electrode (SPCE). Electrochemical experiments on the proposed biosensor (SPCE|ABTS-CNT|Nafion) have revealed promising sensing characteristics for creatinine and human serum albumin detection. Practical urine tests has demonstrated the capability of the proposed urine detection system for UACR detection with both the power-efficient readout ASIC and the ABTS-CNT biosensor. A user-friendly prototype has also been designed which can be useful for either personal health administrationor homecare.

Instantaneous Self-Powered Sensing System Based on Planar-Structured Rotary Triboelectric Nanogenerator.

Self-powering electronics by harvesting mechanical energy has been widely studied, but most self-powering processes require a long time in the energy harvesting procedure, resulting in low efficiency or even system failure in some specific applications such as instantaneous sensor signal acquisition and transmission. In order to achieve efficient self-powered sensing, we design and construct an instantaneous self-powered sensing system, which puts heavy requirements on generator’s power and power management circuit. Theoretical analysis and experimental results over two types of generators prove that the planar-structured rotary triboelectric nanogenerator possesses many advantages over electromagnetic generator for the circumstances of instantaneous self-powering. In addition, an instantaneous driving mode power management circuit is also introduced showing advanced performance for the instantaneous self-powering sensing system. As a proof-of-concept, an integrated instantaneous self-powered sensing system is demonstrated based on Radio-Frequency transmission. This work demonstrates the potential of instantaneous self-powered sensing systems to be used in a wide range of applications such as smart home, environment monitoring, and security surveillance.

A Wirelessly Rechargeable AA Battery Using Electrodynamic Wireless Power Transmission

We report the design, fabrication, and characterization of a prototype that meets the form, fit, and function of a household 1.5 V AA battery, but which can be wirelessly recharged without removal from the host device. The prototype system comprises a low-frequency electrodynamic wireless power transmission (EWPT) receiver, a lithium polymer energy storage cell, and a power management circuit (PMC), all contained within a 3D-printed package. The EWPT receiver and overall system are experimentally characterized using a 238 Hz sinusoidal magnetic charging field and either a 1000 µF electrolytic capacitor or a lithium polymer (LiPo) cell as the storage cell. The system demonstrates a minimal operating field as low as 50 µTrms (similar in magnitude to Earth’s magnetic field). At this minimum charging field, the prototype transfers a maximum dc current of 50 µA to the capacitor, corresponding to a power delivery of 118 µW. The power effectiveness of the power management system is approximately 49%; with power effectiveness defined as the ratio between actual output power and the maximum possible power the EWPT receiver can transfer to a pure resistive load at a given field strength.

Simple and highly efficient intermittent operation circuit for triboelectric nanogenerator toward wearable electronic applications

Triboelectric nanogenerator (TENG) is a promising power source toward the realization of self-powered wearable electronics. However, because of its pulsed output, a power management circuit, such as an intermittent operation circuit and AC–DC converter, is required to drive electronic devices. In this study, we propose a simple and highly efficient intermittent operation circuit composed of a programmable unijunction transistor. The energy transfer efficiency from the storage capacitor to the load reached 89%. We demonstrated that the intermittent circuit can be used to drive electronic devices such as stopwatches and wristwatches using the electricity generated by a carbon-nanotube-based stretchable TENG.

A Thermoelectric Energy Harvester Based on Microstructured Quasicrystalline Solar Absorber.

As solar radiation is the most plentiful energy source on earth, thermoelectric energy harvesting emerges as an interesting solution for the Internet of Things (IoTs) in outdoor applications, particularly using semiconductor thermoelectric generators (TEGs) to power IoT devices. However, when a TEG is under solar radiation, the temperature gradient through TEG is minor, meaning that the TEG is useless. A method to keep a significant temperature gradient on a TEG is by using a solar absorber on one side for heating and a heat sink on the other side. In this paper, a compact TEG-based energy harvester that features a solar absorber based on a new class of solid matter, the so-called quasicrystal (QC), is presented. In addition, a water-cooled heat sink to improve the temperature gradient on the TEG is also proposed. The harvester is connected to a power management circuit that can provide an output voltage of 3 V and store up to 1.38 J in a supercapacitor per day. An experimental evaluation was carried out to compare the performance of the proposed QC-based harvester with another similar harvester but with a solar absorber based on conventional black paint. As a result, the QC-based harvester achieved 28.6% more efficient energy generation and achieved full charge of a supercapacitor around two hours earlier. At last, a study on how much the harvested energy can supply power to a sensor node for Smart agriculture during a day while considering a trade-off between the maximum number of measurements and the maximum number of transmission per day is presented.

Sports training monitoring of energy-saving IoT wearable devices based on energy harvesting

In this paper, energy-saving the Internet of Things wearable devices based on energy harvesting used to monitor sports training. The energy sources involved include radiofrequency energy, mechanical energy, and thermal energy. The power management circuit structure designed to match its application with energy harvesting components as the core to ensure that the collected energy can meet the power conditions of electrical equipment. Completed the hardware design of the entire human motion information collection system based on energy-saving IoT wearable devices, first gave the overall design plan of the system, and on this basis, adopted the modular design of the system, and designed the posture measurement separately unit, positioning unit, and data storage and communication unit. Among them, the attitude measurement unit designed according to the different needs in actual use, and the miniature attitude measurement unit and the multi-function attitude measurement unit are designed. The data storage and communication unit designed to ensure data storage and for the reliability of transmission, an offline data storage unit and a Bluetooth remote communication unit designed respectively. The system adopts a modular design, which makes the system more convenient to expand and upgrade, and has better applicability and reliability.

SSVM: An Ultra-Low-Power Strain Sensing and Visualization Module for Long-Term Structural Health Monitoring.

Structural health monitoring (SHM) is crucial for quantitative behavioral analysis of structural members such as fatigue, buckling, and crack propagation identification. However, formerly developed approaches cannot be implemented effectively for long-term infrastructure monitoring, owing to power inefficiency and data management challenges. This study presents the development of a high-fidelity and ultra-low-power strain sensing and visualization module (SSVM), along with an effective data management technique. Deployment of 24-bit resolution analog to a digital converter and precise half-bridge circuit for strain sensing are two significant factors for efficient strain measurement and power management circuit incorporating a low-power microcontroller unit (MCU), and electronic-paper display (EPD) enabled long-term operation. A prototype for SSVM was developed that performs strain sensing and encodes the strain response in a QR code for visualization on the EPD. For efficient power management, SSVM only activated when the trigger-signal was generated and stayed in power-saving mode consuming 18 mA and 337.9 μA, respectively. The trigger-signal was designed to be generated either periodically by a timer or intentionally by a push-button. A smartphone application and cloud database were developed for efficient data acquisition and management. A lab-scale experiment was carried out to validate the proposed system with a reference strain sensing system. A cantilever beam was deflected by increasing load at its free end, and the resultant strain response of SSVM was compared with the reference. The proposed system was successfully validated to use for long-term static strain measurement.

0.13 μm Low-Power CMOS Current Starved VCO for Vibration Energy Harvesters

This work presents a current starved voltage-controlled oscillator (VCO) based on the standard 0.13- $\mu \text{m}$ CMOS process. Incorporated with the power management circuit (PMC), the current starved VCO generates an average periodic signal at a frequency of 84.81 kHz. In addition, to assure that the VCO has a stable periodic signal output regarding the varied control voltage, a voltage reference is realized. The proposed architecture makes full use of subthreshold and deep triode MOSFETs without any other components. A reference voltage of 258.35 mV is obtained in response to the supply voltage 1.0–3.2 V. The architecture exhibits a linear sensitivity of 0.49%/V at 27 °C. Power consumption of the proposed circuit is $3.546~\mu \text{W}$ at 3 V of the voltage supply. The output of the architecture leads to a time-control local oscillator, which can be employed in a PMC for vibration energy harvesters.

A Review of Power Management Integrated Circuits for Ultrasound-Based Energy Harvesting in Implantable Medical Devices

This paper aims to review the recent architectures of power management units for ultrasound-based energy harvesting, while focusing on battery-less implantable medical devices. In such systems, energy sustainability is based on piezoelectric devices and a power management circuit, which represents a key building block since it maximizes the power extracted from the piezoelectric devices and delivers it to the other building blocks of the implanted device. Since the power budget is strongly constrained by the dimension of the piezoelectric energy harvester, complexity of topologies have been increased bit by bit in order to achieve improved power efficiency also in difficult operative conditions. With this in mind, the introduced work consists of a comprehensive presentation of the main blocks of a generic power management unit for ultrasound-based energy harvesting and its operative principles, a review of the prior art and a comparative study of the performance achieved by the considered solutions. Finally, design guidelines are provided, allowing the designer to choose the best topology according to the given design specifications and technology adopted.

A Small Hybrid Power System of Photovoltaic Cell and Sodium Borohydride Hydrolysis-Based Fuel Cell.

Although the hybrid power system that combines a photovoltaic cell and a lithium-ion battery is increasingly mature and practical, long-lifetime auxiliary power will be still needed in severe weather conditions. A small-volume hydrogen–oxygen fuel cell system based on the hydrolysis of NaBH4 is designed. The fuel cell system contains a tiny hydrogen generator, a hydrogen cleaner, and a small fuel cell stack consisting of three units in series. The relationship between the amount of catalyst and output performance is discussed. The long-time discharging results indicate that the fuel cell system has high power capacity. The compact design allows the fuel cell system to integrate the structure with a photovoltaic cell and lithium-ion cell and forms a hybrid power system with a small package. The power management circuit for these power sources without logic devices is designed and tested. The control strategy selects the photovoltaic–battery subsystem as the primary power source, and the fuel cell subsystem works as the backup power source to handle the circumstance when the energy stored in the battery is exhausted. The test results show that the power management system could switch the power supply automatically and timely under various emergency conditions, and the output voltage remains stable all the time.

THE ADAPTIVE MANAGEMENT DEVELOPMENT FOR THE ENTERPRISE’S STRATEGIC COSTS UNDER THE FOURTH INDUSTRIAL REVOLUTION CONDITIONS

Modern enterprises operate under the fourth industrial revolution conditions, which are characterized by radical changes in production processes through digitalization, big data processing, and cyber-physical systems usage. At the same time, accelerating the market environment’s transformations requires the business entities to adapt to the changes of the environmental conditions. With this transformation in mind, the purpose of the article is to form a theoretical and methodological basis for the industrial enterprises’ strategic cost management organization. The semantic analysis results of the “cost management” concept interpretations, performed by using the Advego keyword search system, have been used as a basis for achieving the article goal. The cost management objects systematization has been carried out. The ways to such objects decomposition for management purposes has been justified. The additional cost management objects, such as the company’s presence parameters in the value creation network, characteristics of the enterprise’s strategic choice, the company’s business model elements, the company’s element architectural description, have been offered. The selection of cost management objects has determined the author’s hypothesis about the need to add strategicity to the cost management circuits, which should be implemented on an ongoing basis and in expanding the cost management circuits’ adaptive properties. The following classification features have been introduced as part of the control object’s decomposition: strategic costs, critical costs, and costs adaptability. The description of the cost management system corresponded with the fourth industrial revolution features has been given by the cost management subject structuring and the elements of the cost management system systematization. The contours allocation of tactical and strategic adaptation to business conditions changes within the enterprise’s cost management system has been proposed.

Free‐Fixed Rotational Triboelectric Nanogenerator for Self‐Powered Real‐Time Wheel Monitoring

AbstractDeveloping an applicable triboelectric nanogenerator (TENG) for train wheel energy harvesting is a key step to meet the urgent need of wheel safety monitoring. Herein, an innovative design of free‐fixed TENG (FF‐TENG) is reported, without a serious negative impact on the wheel. The key of this design is the magnets fixed on the device and bogie, providing attractive force to immobilize the stator. With a rotational structure, FF‐TENG can provide a high short‐circuit current of 55 µA, an open‐circuit voltage of 500 V, and a charge of 235 nC at a rotation speed of 400 rpm. At an external load resistance of 10 MΩ, FF‐TENG delivers the maximum power of 15.68 mW. Furthermore, the superior robustness of FF‐TENG in vibration environment is proved. In addition, a power management circuit designed by LTC 3588 is tested for more efficient capacitor charging, leading to better performance to power electronics. Finally, a self‐powered real‐time wheel temperature and wheel speed monitoring system is developed with FF‐TENG as a safety alert demo for feasibility demonstration. Given the rational structure design and high performance, this work paves a practical way for TENGs in the field of intelligent transportation.

Smart Power Unit—mW-to-nW Power Management and Control for Self-Sustainable IoT Devices

Self-sustainability and intelligence will be critical features of the next generation of Internet of Things devices. Power management circuits need to be energy-efficient in multiple power modes, from nW sleep to mW active, and to support energy harvesting (EH) from multiple environmental sources. This article presents an adaptive and firmware-configurable power supply unit that enables intelligent devices to operate in the sub μW range while achieving self-sustainability through EH. The microcontroller-based design allows efficient conversion from batteries, dc, ac environmental sources, and nA quiescent currents. Source and load power points are decoupled with multiple dc–dc converters aiming to supply loads with adaptive voltage scaling and achieving high reliability. Experimental results show the flexibility and efficiency of this approach: the proposed power supply unit achieves a quiescent current of 54 nA and a maximum peak load current of 300 mA, delivered with an end-to-end power efficiency above 85%.

Rotational pulsed triboelectric nanogenerators integrated with synchronously triggered mechanical switches for high efficiency self-powered systems

Abstract With the merits of zero internal equivalent resistance and maximized output energy, the pulsed mode triboelectric nanogenerators (TENGs) can achieve impedance matching with the power management circuits (PMCs), showing wide application prospects in self-powered systems. The key for developing Pulsed-TENGs lies in designing synchronously triggered mechanical switches (STMSs). However, rotational TENGs, as a promising configuration for harvesting mechanical energy, have rarely been designed as pulsed mode because of the difficulty in fabricating rational STMSs. Herein, rotating freestanding triboelectric-layer Pulsed-TENGs (RF-Pulsed-TENGs) are realized through integrating STMSs on triboelectric layers in one step by printed circuit board process. Since the on-off states of the STMSs can match well with the rotation frequency, the output voltage and energy of the RF-Pulsed-TENGs are maximized regardless of the rotation frequency or load resistance. Both alternating current and unidirectional current output RF-Pulsed-TENGs have been realized, and the energy storage efficiency of their corresponding passive PMCs can reach 51.6% and 52.0%, respectively. The system consisting of a gearbox, a passive PMC, and a RF-Pulsed-TENG has been demonstrated to power a range of electronic devices, such as calculators, electronic watches, and temperature/humidity meters, offering significant advantages and promising applications in efficient mechanical energy harvesting and self-powered sensing.

Experimentation of a Wearable Self‐Powered Jacket Harvesting Body Heat for Wearable Device Applications

The development of special wearable/portable electronic devices for health monitoring is rapidly growing to cope with different health parameters. The emergence of wearable devices and its growing demand has widened the scope of self‐powered wearable devices with the possibility to eliminate batteries. For instance, the wearable thermoelectric energy harvester (TEEH) is an alternate to batteries, which has been used in this study to develop four different self‐powered wearable jacket prototypes and experimentally validated. It is observed that the thermal resistance of the cold side without a heat sink of prototype 4 is much greater than the rest of the proposed prototypes. Besides that, the thermal resistance of prototype 4 heat sinks is even lower among all proposed prototypes. Therefore, prototype 4 would have a relatively higher heat transfer coefficient which results in improved power generation. Moreover, an increase in heat transfer coefficient is observed with an increase in the temperature difference of the cold and hot sides of a TEEH. Thus, on the cold side, a heat flow increases which benefits heat dissipation and in turn reduces the thermal resistance of the heat sink. Besides that, the developed prototypes on people show that power generation is also affected by factors like ambient temperature, person’s activity, and wind breeze and does not depend on the metabolism. A different mechanism has been explored to maximize the power output within a 16.0 cm2 area, in order to justify the wearability of the energy harvester. Furthermore, it is observed that during the sunlight, any material covering the TEEH would improve the performance of prototypes. Prototypes are integrated into jacket and studied extensively. The TEEH system was designed to produce a maximum delivering power and power density of 699.71 μW and 43.73 μW/cm2, respectively. Moreover, the maximum voltage produced is 62.6 mV at an optimal load of 5.6 Ω. Furthermore, the TEEH (prototype 4) is connected to a power management circuit of ECT310 and LTC3108 and has been able to power 18 LEDs.

Design and development of eco-friendly cutlery out of paper waste through molding next generation waste management

The waste of paper or the paper dump is a serious problem and its occurrence is widespread in various institutions. Wastepaper can be recycled to produce some important and usable products that are ecological and biodegradable. For example, it is used to extract new paper from the old by chemical decomposition. Other products such as paper plates, paper cups, paper spoons, tiles, toys, crafts, etc. can be formed from the slurry. This project also initiates a mould that makes cups and plates from the wastepaper management circuit. With learning institutions being the main consumers, most paper are usually eliminated after its use. The waste remains undeveloped and unused, although is a valuable resource. Studying the design of a manual, economical and efficient paper recycling machine, it can be surmised that the design uses the integration of the knowledge gained about the recycling technology that exists manually from the paper recycling machines used to form a cheap but effective paper recycling system. The advantages of the machine are not only of recycled paper, but also the advantages of the interaction of the manual drive system, which will also reduce the high cost. As the design is not 100% effective, the transmission, belt and chain transmission correspond to the estimated 90% efficiency using the 90% for the design. The power consumption for the design is 450 W and since an average user can produce 100 W constant, it takes 5 people to drive the machine.

Self-Powered Wireless Sensor Node for Smart Railway Axle Box Bearing via a Variable Reluctance Energy Harvesting System

In recent years, the wireless sensor node (WSN) has been used in condition monitoring of the railway axle box bearing to guarantee the safety of the high-speed train. This article proposes a variable reluctance energy harvesting system to power the WSN for extending the service life of the WSN integrated within the smart bearing. The variable reluctance energy harvesting system consists of a variable reluctance energy harvester (VREH) and a power management circuit (PMC), which is able to convert the rotation motion energy into electrical energy efficiently. The key geometrical parameters of the VREH were investigated to obtain the optimal energy harvesting performance by the theoretical modeling and the finite-element analysis. The PMC was designed in the LTspice to achieve the purposes of impedance matching, voltage boosting, rectification, and regulation. The energy harvester was prototyped and used for powering a WSN embedded in the bearing. The powering capability of the energy harvesting system was experimentally verified under the rotation speed range of 400–1200 r/min. Under the rotational speed of 1200 r/min and optimal impedance matching, the generated power of the prototype of harvester reaches 76.05 mW and the charging efficiency of PMC is 52.6%. It is proven that the designed energy harvesting system is capable of powering the WSN for detecting the rotation speed, vibration, strain, and temperature information of the bearing. The proposed smart bearing system has a great potential for improving the reliability of the high-speed train.

Labor productivity management in the competence system at the regional level

Importance. Economic recovery after the pandemic is associated with the transition of production to more efficient technological solutions aimed at increasing labor productivity. Optimization of existing production processes, increasing the efficiency of proven technologies should be accompanied by the organization of a parallel advanced process of developing new promising systems and technologies. The implementation of these tasks is associated with a number of difficulties associated with the low qual- ity of management systems. One of the significant problems was the lack of a training and retraining system built into the full technological and marketing cycle of production. Objectives. The purpose of the study is to develop a concept of a management system based on a com- petency-based approach and aimed at increasing labor productivity at the regional level. The article developed a management model that allows to combine various departmental and corporate interests. For the study, the regional level was chosen as the base one, since the main set of issues necessary for the dynamic development of production processes are in the competence of regional state, industrial and educational structures. Methods. The work used such methods of economic research as: modeling, the method of scientific abstractions, analysis and synthesis, systemic and functional approaches; special research methods: analytical and comparative methods. Conclusions and Relevance. The proposed model allows the use of scientific developments to increase production efficiency and includes a system of scientific and educational competencies in the regional management circuit. The management model was focused on the implementation of methodologies to achieve the lowest cost results in the short term, which should be part of the strategic management framework. The article highlighted the operational level of increasing labor productivity as the most amenable to formalization and identification of indicators, and developed principles for the formation of indicators of labor productivity. The practice of applying new approaches to management by organi- zations had shown the need to coordinate the management of labour productivity at the macroeconom- ic level, since, in many respects, key management decisions should be made at the regional and federal levels due to the separation of departments and corporations, which could not agree on a single tech- nological policy. The theoretical rationale for the economic model of digital peri-ode is gaining a new socio-economic content, which we have begun and continue to develop in this publication.