Energy Harvesting Architecture Research Articles

UAV aided NOMA relaying with energy harvesting architecture: Performance analysis

In this work, we consider a dual hop Non Orthogonal Miltiple Access (NOMA) based communication network between Source S and two destination users UA , UB which is aided by an Unmanned Aerial Vehicle (UAV) relay R. The energy constrained UAV relay harvests energy from signal transmitted by the source through Power Splitting (PS) and further transmits the signal using Amplify and Forward (AF) protocol to the destination users through NOMA. For the proposed network, we derive analytical expressions for outage probability and ergodic capacity. The impact of parameters like PS ratio and UAV altitude is studied on the overall system performance. Further, the performance of the proposed system is also compared with Orthogonal Multiple Access (OMA) scheme. The results obtained show that the energy harvesting capacity of UAV is significantly affected under Linear and Non Linear EH models. The numerical analysis done is verified through Monte Carlo Simulations.

A model-based approach for formal verification and performance evaluation of energy harvesting architectures in IoT systems: A case study of a long-term healthcare application

Energy harvesting plays a significant role in the Internet of Things (IoT). Indeed, although numerous approaches exist to limit the system’s power consumption, the energy provided by the battery remains constrained, thereby limiting the system’s lifetime. Energy harvesting represents an interesting technique that allows a set of devices in an IoT architecture to operate for a potentially infinite time without the need for battery replacement or recharge. This work presents a formal modeling framework for the performance evaluation of energy harvesting architectures and strategies in IoT systems. We present a model-based approach using UPPAAL to model and analyze IoT device lifetimes and capture the energy-related behavior of nodes and various energy harvesters. Furthermore, the model is calibrated using measurements acquired from real-life IoT applications to demonstrate the effectiveness of the proposed model and its ability to investigate various energy-related aspects.

Predictive lumped model for a tunable bistable piezoelectric energy harvester architecture

In this article, we propose the modelling of a tunable bistable piezoelectric energy harvester (or BPEH) architecture. The latter is a type of ambient energy converter that continues to gain attention due to their wideband frequency response. As the non-linear dynamics of BPEHs imply significant modeling complexity, dynamic lumped models are necessary to predict BPEHs’ dynamic response and should fit the type of architecture studied. The BPEH architecture of interest uses post-buckled beams to create bistability and an amplified piezoelectric actuator (or APA) to convert the ambient vibrations. To date, no dynamic lumped models have been found in existing literature that account for both the electromechanical conversion and the dynamic behavior of buckled beams, with a specific focus on their axial and bending stiffness, for this BPEH architecture. Additionally, the proposed BPEH architecture offers buckling level tunability, which is achieved using an additional APA. Hence, the aim of this paper is to propose a new lumped model for a BPEH architecture that considers the effect of the post-buckled beams’ stiffness and of the additional APA through an elasticity factor κ― . This lumped model is established using Euler Lagrange equations and is experimentally validated on a tunable BPEH prototype. This validation shows an average relative error below 6% between the model predictions and experimental dynamic response of the prototype to an ascending frequency sweep, compared to an average relative error that is around 14% for the model proposed in literature. Moreover, numerical simulations using the proposed model lead to the conclusion that there is an optimal elasticity factor κ― that ensures the maximum power output while maintaining the frequency bandwidth.

A High-Efficiency, Ultrawide-Dynamic-Range Radio Frequency Energy Harvester Using Adaptive Reconfigurable Technique

This paper presents a novel adaptive reconfigurable rectifier architecture for radio frequency energy harvesting (RFEH); in addition, a new metric for high-efficiency dynamic range (DR) is proposed. The presented rectifier architecture is based on a double-sided diode-feedback cross-coupled differential-drive rectifier (CCDR) structure incorporating self-body bias for reconfigurable operation. An adaptive structure based on a Schmitt trigger is proposed to adaptively switch the rectifier connection without auxiliary voltage (Vaux), with two rectifier stages in parallel at low power and in series at high power. The system is simulated at a 180 nm CMOS process and the results show more than 17 dB DR at 900 MHz, with efficiency higher than 50% at a 100 kΩ load.

Remarkable enhancement of the adsorption and diffusion performance of alkali ions in two-dimensional (2D) transition metal oxide monolayers via Ru-doping

Transition metal oxides (TMO) are the preferred materials for metal ion battery cathodes because of their high redox potentials and good metal-ion intercalation capacity, which serve as an outstanding replacement for layered sulphide. In this work, using first-principles calculations based on Density functional theory approach, we explored the structural and electronic properties which comprise of adsorption and diffusion behaviour along with the analysis of voltage profile and storage capacity of Ru doped two-dimensional transition metal oxide MnO2\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$MnO_{2}$$\\end{document}, CoO2\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$CoO_{2}$$\\end{document}, and NiO2\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$NiO_{2}$$\\end{document} monolayers. The adsorption of alkali ions (Li, Na) to the surface of TMOs is strengthened by Ru-atom doping. Ru doping enhanced the adsorption energy of Li/Na-ion by 25%/11% for MnO2\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$MnO_{2}$$\\end{document}, 8%/13% for CoO2\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$CoO_{2}$$\\end{document}, and 10%/11% NiO2\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$NiO_{2}$$\\end{document} respectively. The open circuit voltage (OCV) also increases due to the high adsorption capacity of doped Monolayers. Ru doping makes the semiconducting TMOs conduct, which is suitable for battery application. As alkali ion moves closer to the dopant site, the adsorption energy increases. When alkali ions are close to the vicinity of doping site, their diffusion barrier decrease and rises as they go further away. Our current findings will be useful in finding ways to improve the storage performance of 2D oxide materials for application in energy harvesting and green energy architecture.

Empowering Sustainability: The Promise of Energy Harvesting from Wheel Motion (Experiment and simulation)

The evident rise in the demand for durable and environmentally friendly power solutions in the future has spurred the advancement of inventive energy harvesting architectures, specifically emphasizing renewable sources such as wind and solar power. This study aims to make a valuable contribution to the field of energy harvesting by introducing an original concept: the utilization of energy generated from wheel motion. The proposed method involves strategically positioning magnets and copper coils inside the hubcap's spoke. As the wheel rotates, the magnets' movement induces a winding action within the coils. This dynamic interaction, in accordance with Faraday's Law, generates an electric current within the coil. To assess the effectiveness of this approach, a meticulously designed experimental setup was implemented, measuring the output voltage of the electromagnetics. These measurements provide significant insights into the energy harvesting potential of this method. Furthermore, to ensure the reliability and accuracy of the findings, a numerical simulation was conducted, enabling a comprehensive analysis and validation of the experimental results. By exploring the concept of wheel motion energy harvesting, this research strives to contribute to the development of sustainable and efficient power generation solutions. The integration of electromagnetic principles into this innovative approach highlights the viability of utilizing wheel motion as a practical energy source. These findings pave the way for further advancements in energy harvesting technologies, fostering a more sustainable and environmentally friendly future.

The mechanism parts of mechanical motion rectifier to produce energy from third pedal in automotive

Energy harvesting architectures, such as wind turbines and solar panels, have become a necessity as renewable energy sources have grown in popularity. The most promising source of electric energy appears to be electromechanical energy harvesting, as it generates significant amounts of electricity that can be utilized in numerous ways. This research supports and supplements the automotive, regardless of how much and how effectively power is generated. Essentially, when the driver touches the throttle or brake pedal, the energy-harvesting pedal receives motion from them through a mechanical connection rod. Considering its utility in charging electric cars, it is considered one of the most useful sources of electricity.

A Sub-μW Energy Harvester Architecture With Reduced Top/Bottom Plate Switching Loss Achieving 80.66% Peak Efficiency in 180-nm CMOS

This article presents a 25 nW–2.4 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu$</tex-math> </inline-formula> W switched-capacitor-based solar energy harvester with integrated maximum power point tracking (MPPT). The proposed dc–dc converter avoids charging and discharging of top and bottom plate parasitic capacitors by switching both the terminals of energy source as opposed to switching just one terminal. As a result, the energy lost in switching the top and bottom plate parasitic capacitors is zero joules, which helps to achieve highly efficient switched capacitor architecture for harvesting sub 1- <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu$</tex-math> </inline-formula> W energy. The proposed dc–dc converter achieves same charge redistribution loss (CRL) as that of a cross-coupled dc-dc converter with half the required number of capacitors. The proposed harvester is implemented in 180 nm CMOS process and achieves an efficiency of 80% while delivering 1- <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu$</tex-math> </inline-formula> W output and achieves a peak efficiency of 80.66% at 2.4- <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu$</tex-math> </inline-formula> W output while maintaining a regulated output of 1.8 V.

A Power Management System for Hybrid Energy Harvesting From Multiple Multitype Sources and Ultrawide Range Source Tracking

This article presents a power management system (PMS) for hybrid energy harvesting from multiple multitype sources. Three key features of the proposed approach are 1) a simple architecture for hybrid energy harvesting from multiple multitype sources by sharing a single inductor, 2) a backup power controller (BPC) for recycling surplus energy, and 3) an efficient boost–buck conversion (B2C) mode for tracking multiple sources within a single cycle. The power stages of the PMS consist of an active bias-flip rectifier (ABFR) for ac sources, three input low-voltage boost converters (3LVBC), and a high-voltage buck converter for dc sources. The B2C mode efficiently combines the operation of the 3LVBC and HVBC. By sharing an inductor in B2C mode, the ABFR increases the overall input power ( <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">P</i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">IN</sub> ) by aggregating the power from the hybrid sources. The proposed PMS operates under four modes depending on the load conditions detected by the BPC. This approach improves the average harvesting efficiency using the auxiliary output paths and two storage nodes. For per-source maximum power point tracking, adaptive impedance matching and perturb and observe techniques are used. The integrated circuit (IC) part of the PMS is fabricated in a 180 nm process. The measured tracking efficiency is higher than 92% for a wide source resistance range from 2 Ω to 2 kΩ (1000× range). An end-to-end efficiency of up to 92.5% is achieved. The energy harvesting from multiple multitype sources significantly extends the output power range from 0.053 μW to 132600 μW. All the functions of the IC are realized with only 900 nW.

Bioinspired heterogeneous and hierarchical porous structure of oxo-graphene assembly for spontaneous energy harvesting from air

Environmentally adaptive energy harvesting without additional stimuli is glamorous for next-generation energy technology. The ubiquitous air offers an alternative, but existing carbon-based moisture-electric generators can only generate desultory or insufficient power under air, owing to the absence of sustaining and effective energy harvesting and conversion architecture and mechanism. Here an eco-friendly and direct solid molding strategy was applied to rapidly fabricate heterogeneous oxo-graphene (H-mrGO) assembly. Inspired by root and trunk in natural vascular plants, rational fabrication of hierarchical porous structure immensely enhances spontaneous absorption of water molecules from air, which further induces rapid proton diffusion because of self-maintained and huge concentration difference. A single H-mrGO device can spontaneously produce an ultrahigh voltage of ∼1.39 V under air (RH ≈ 99%) and a high voltage of ∼1.2 V at low humidity (∼30%) is obtained, accompanied by a power density of ∼1.1 W/m2. Meanwhile, it realizes a sustaining power output for external resistance over 40,000 s with good stability. Connecting several H-mrGO devices linearly magnifies voltage up to 10 V and obtains a wearable device, which can directly power different electronics without additional transverters. This work demonstrates the feasibility of a sustaining moisture-electric energy-harvesting strategy that loosens rigorous requirements of location or environmental conditions.

High-efficient energy harvesting architecture for self-powered thermal-monitoring wireless sensor node based on a single thermoelectric generator

In recent years, research on transducers and system architectures for self-powered devices has gained attention for their direct impact on the Internet of Things in terms of cost, power consumption, and environmental impact. The concept of a wireless sensor node that uses a single thermoelectric generator as a power source and as a temperature gradient sensor in an efficient and controlled manner is investigated. The purpose of the device is to collect temperature gradient data in data centres to enable the application of thermal-aware server load management algorithms. By using a maximum power point tracking algorithm, the operating point of the thermoelectric generator is kept under control while using its power-temperature transfer function to measure the temperature gradient. In this way, a more accurate measurement of the temperature gradient is achieved while harvesting energy with maximum efficiency. The results show the operation of the system through its different phases as well as demonstrate its ability to efficiently harvest energy from a temperature gradient while measuring it. With this system architecture, temperature gradients can be measured with a maximum error of 0.14 ^{circ }C and an efficiency of over 92% for values above 13 ^{circ }C and a single transducer.

Differential Privacy and IRS Empowered Intelligent Energy Harvesting for 6G Internet of Things

In the era of the sixth generation (6G), the deployment of massive Internet of Things (IoT) generates and processes large amounts of data, resulting in high energy demand and huge challenges to the energy-limited IoT devices. To achieve green and sustainable communication, energy harvesting is a feasible technology to prolong the lifetime of IoT. However, the existing energy harvesting architecture cannot guarantee the privacy of energy users while improving the intelligence and effectiveness of energy transmission. To solve these issues, we propose a differential privacy and intelligent reflecting surface empowered privacy-preserving energy harvesting framework for 6G-enabled IoT. First, a secure and intelligent energy harvesting framework is designed, which includes an intelligent reflecting surface-aided radio frequency power transmission mechanism and a differential privacy-based energy harvesting mechanism. Second, an exponential mechanism-based privacy-preserving energy harvesting scheme is established, where we analyze the adversary mode, propose the differential privacy-enabled location-preserving algorithm, and provide security analysis and proof. Third, we quantify the user satisfaction for energy harvesting and propose a deep reinforcement learning empowered resource allocation scheme to maximize the weighted satisfaction of all system users. Finally, simulation results show the effectiveness of the proposed secure and intelligent energy harvesting architecture for 6G IoT.

Textile Materials for Wireless Energy Harvesting

Wireless energy harvesting, a technique to generate direct current (DC) electricity from ambient wireless signals, has recently been featured as a potential solution to reduce the battery size, extend the battery life, or replace batteries altogether for wearable electronics. Unlike other energy harvesting techniques, wireless energy harvesting has a prominent advantage of ceaseless availability of ambient signals, but the common form of technology involves a major challenge of limited output power because of a relatively low ambient energy density. Moreover, the archetypal wireless energy harvesters are made of printed circuit boards (PCBs), which are rigid, bulky, and heavy, and hence they are not eminently suitable for body-worn applications from both aesthetic and comfort points of view. In order to overcome these limitations, textile-based wireless energy harvesting architectures have been proposed in the past decade. Being made of textile materials, this new class of harvesters can be seamlessly integrated into clothing in inherently aesthetic and comfortable forms. In addition, since clothing offers a large surface area, multiple harvesting units can be deployed to enhance the output power. In view of these unique and irreplaceable benefits, this paper reviews key recent progress in textile-based wireless energy harvesting strategies for powering body-worn electronics. Comparisons with other power harvesting technologies, historical development, fundamental principles of operation and techniques for fabricating textile-based wireless power harvesters are first recapitulated, followed by a review on the principal advantages, challenges, and opportunities. It is one of the purposes of this paper to peruse the current state-of-the-art and build a scientific knowledge base to aid further advancement of power solutions for wearable electronics.

Wireless Information and Power Transfer for IoT: Pulse Position Modulation, Integrated Receiver, and Experimental Validation

Simultaneous wireless information and power transfer (SWIPT) has emerged as a viable technique to energize and connect low-power autonomous devices and enable future Internet of Things (IoT). A major challenge of SWIPT is the energy consumption of the receiver of such low-power devices. An attractive low-power solution consists of an integrated information decoder (ID) and energy harvester (EH) architecture for SWIPT receiver (IntRx) where the received radiofrequency (RF) signal is first rectified before being used for information decoding. Such architecture eliminates the need for energy-consuming RF components, such as local oscillators and mixers. This article proposes a novel modulation and demodulation method for the IntRx SWIPT architecture based on pulse position modulation (PPM) where information is encoded in the position of the pulse. The new method transmits high amplitude pulses to increase the peak-to-average power ratio (PAPR) of the transmit signal and exploits the EH’s nonlinearity so as to boost the harvested dc power. Simultaneously, the information can be decoded from the rectifier signal by simply finding the position of the pulse in a certain symbol duration. We have analyzed both the information and the power transfer performance of the newly proposed PPM for IntRx SWIPT theoretically, numerically, and experimentally. To that end, we have established a SWIPT system testbed in an indoor environment by prototyping a base station to transfer information-power signal and the IntRx SWIPT receiver, including ID and EH blocks. The performance evaluation of the PPM was carried out in various conditions, and the results have been compared and contrasted to conventional signals. Theoretical, numerical, and experimental results highlight the significant benefits of the proposed PPM scheme to enhance the power transfer performance and operate information decoding with low-power consumption.

Time-domain model and optimization for single-axis kinetic energy harvesters driven by arbitrary non-harmonic excitation

Energy harvesting is employed to extend the life of battery-powered devices, however, demanding applications such as wildlife tracking collars, the operating conditions impose size and weight constraints. They also only provide non-harmonic mechanical motion, which renders much of the existing literature inapplicable, which focuses on harvesting energy from harmonic mechanical sources. As a solution, we propose an energy harvesting architecture that consists of variable number of evenly-spaced magnets, forming a fixed assembly that is free to move through a series of evenly-spaced coils, and is supported by a magnetic spring. We present an electromechanical model for this architecture, and evolutionary optimization process that finds the model parameters which describe the time-domain behaviour observed in ground truth measurements. The resulting model can predict the time-domain behaviour of the energy harvester for any configuration of the proposed architecture and for any mechanical excitation. We also propose an optimization process that, using the electromechanical model, optimizes the energy harvester configuration to maximize the power delivered to a resistive load. The resulting optimized harvester design is specific to the particular kind of non-harmonic mechanical excitation to which it will be exposed. To demonstrate the effectiveness of our proposed model and optimization procedure, we constructed four energy harvesters, each with different configurations, and compared their measured behaviour with that predicted by the model, given an excitation that approximates footstep-like motion. We show that the model predictions were consistently within 25% of the RMS load voltage. We then synthesize an optimal energy harvester using the proposed optimization process. The resulting optimal design was constructed and tested using the same footstep-like excitation, and delivered an average power of 1.526 mW to a 30Ωload. This is a 2.8-fold improvement over an unoptimized reference design. We conclude that our proposed behavioural model and optimization process allows the determination of energy harvester designs that are optimized for a non-harmonic and specific input excitation.

(Invited) Solid-Liquid Contact Electrification and Its Use for Energy Harvesting and Self-Powered Applications

The abundance of water on earth provides a large window to utilize the mechanical energy within river currents and ocean waves. In this regard, hydropower harvesting through solid–liquid contact electrification has received considerable interest in the recent past. Despite advancements in nanotechnology, liquid energy harvesting devices, especially solid–liquid triboelectric nanogenerators (S–L TENGs), require efficient engineering of the interfacial properties of their substrates to transfer liquid mass and momentum rapidly with the effective generation/transfer of surface charges. To face this challenge, several parameters such as the selection of material, surface morphology and surface properties are currently being studied to develop a better system architecture for energy harvesting and self-powered application platforms with three different interacting modes of liquid contact. Moreover, several parameters of the contact solvents such as the ionic activity and polarity have been studied to understand the practical applicability of S–L TENGs to harvest energy from different natural and artificial resources. In addition, the scope of harvesting mechanical energy from other volatile organic compounds has been studied recently. Self-powered applications of S–L TENGs in various fields have also been demonstrated by different research groups. This work indicates recent progress in the development of S–L TENGs for the first time in terms of the different properties of solid and liquid contact materials along with their respective applications. Furthermore, the work concludes with perspectives, future opportunities, and major challenges of fabricating S–L TENGs as an efficient energy harvester. References Chatterjee, S. Saha, S. R. Barman, I. Khan, Y.-P. Pao, S. Lee, D. Choi, Z.-H. Lin (2020) Nano Energy, 69, 105092.Z‐H. Lin, G. Zhu, Yu S. Zhou, Y. Yang, P. Bai, J. Chen, Z. L. Wang (2013) Angew. Chem. Int. Ed., 52, 5065-5069.Z-H. Lin, Y. Xie, Y. Yang, S. Wang, G. Zhu, Z. L. Wang (2013) ACS Nano, 7, 4554-4560.Z‐H. Lin, G. Cheng, L. Lin, S. Lee, Z. L. Wang (2013) Angew. Chem. Int. Ed., 52, 12545-12549.Z-H. Lin, G. Cheng, S. Lee, K. C Pradel, Z. L. Wang (2014) Adv. Mater., 26, 4690-4698.

Design and dynamic analysis of integrated architecture for vibration energy harvesting including piezoelectric frame and mechanical amplifier

Vibration energy harvesters (VEHs) can transform ambient vibration energy to electricity and have been widely investigated as promising self-powered devices for wireless sensor networks, wearable sensors, and applications of a micro-electro-mechanical system (MEMS). However, the ambient vibration is always too weak to hinder the high energy conversion efficiency. In this paper, the integrated frame composed of piezoelectric beams and mechanical amplifiers is proposed to improve the energy conversion efficiency of a VEH. First, the initial structures of a piezoelectric frame (PF) and an amplification frame (AF) are designed. The dynamic model is then established to analyze the influence of key structural parameters on the mechanical amplification factor. Finite element simulation is conducted to study the energy harvesting performance, where the stiffness characteristics and power output in the cases of series and parallel load resistance are discussed in detail. Furthermore, piezoelectric beams with variable cross-sections are introduced to optimize and improve the energy harvesting efficiency. Advantages of the PF with the AF are illustrated by comparison with conventional piezoelectric cantilever beams. The results show that the proposed integrated VEH has a good mechanical amplification capability and is more suitable for low-frequency vibration conditions.

SIDO: A single‐input double‐output energy harvesting architecture operating in burst mode with 74.87% peak end‐to‐end efficiency

SummaryA single‐input double‐output (SIDO) energy harvesting architecture implemented with the off‐the‐shelf components is presented in this paper. The proposed SIDO consists of a step‐up converter, a supercapacitor, an output routing control circuit (ORCC), and two output power switches for two loads. Once the supercapacitor charges to a maximum voltage level of nearly 3.7 V, output power switches are successively turned on by the ORCC for a short period of time (i.e., burst mode). The proposed SIDO supports output total power range from 2.694 to 196.76 mW which is in the range of 1.684 to 122.975 times greater than the maximum power available from the ambient energy source (e.g., 1.6 mW) due to the burst mode. Also, the proposed SIDO achieves a peak end‐to‐end efficiency of 74.87% with the self‐starting, that is, no need of batteries other than the ambient energy source. As compared with prior work, the proposed SIDO supports the heaviest loads (e.g., total power of 196.76 mW) and achieves a wide support range with the burst mode operation and starts the operation from the lowest input voltage without the need of the external power source.

Joint power and duty-cycle design using alternating optimization algorithm under energy harvesting architectures

In the emerging sixth generation (6G) communication network, energy harvesting (EH) is a promising technology to achieve the unlimited energy supply and hence makes the wireless communication systems self-sustainable in terms of energy. However, in practice, the efficiency of energy harvesting is often low due to the limited device capability. In this paper, we formulate three types of different EH architectures, i.e., the harvest-use architecture, the harvest-store-use architecture, and the harvest-use-store architecture from the perspective of energy storage efficiency. We propose resource allocation schemes to jointly design the sensor power and duty-cycle via an alternating optimization algorithm under the above EH architectures, in both simultaneous and non-simultaneous harvesting and utilization models, aiming at achieving a higher throughput and energy efficiency. Non-ideal circuit power is also considered. Numerical results show that our proposed schemes under EH architectures outperform the existing classic continuous transmission schemes.

Fusion of Slippery Interfaces and Transistor-Inspired Architecture for Water Kinetic Energy Harvesting

Download : Download high-res image (171KB) Download : Download full-size image Wanghuai Xu is currently a doctoral candidate in the Department of Mechanical Engineering at the City University of Hong Kong and the Department of Precision Machinery and Precision Instrumentation, at University of Science and Technology of China. His research interest focuses on water-based energy harvesting, electrical phenomena at the water-solid interface and bioinspired surface engineering. Download : Download high-res image (243KB) Download : Download full-size image Zuankai Wang is a Professor in the Department of Mechanical Engineering at the City University of Hong Kong. He received his PhD degree in mechanical engineering from Rensselaer Polytechnic Institute, USA, in 2008, his MS degree in microelectronics from Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, in 2003, and BS degree in mechanical engineering from Jilin University, China, in 2000. His research mainly focuses on nature-inspired materials and devices.