Harvesting Potential Research Articles

Optimizing thermoelectric energy harvesting from concrete surfaces: a comparative study of graphite powder and steel fiber reinforcement

ABSTRACT Adopting alternative energy sources becomes imperative, despite the existing technical and practical obstacles in its implementation. This study aimed to explore the energy harvesting potential of the thermoelectric effect on concrete surfaces. By examining the impact of incorporating graphite powder into concrete (at 0.5–2.5% of cement weight) and steel fiber (at 1–2% of concrete volume), we investigated and compared the thermal, electrical, and mechanical properties of concrete. The findings revealed that adding graphite powder at a 2.5% weight-to-cement ratio led to a maximum upper surface temperature of 50.4°C and subsequently generated a maximum voltage of 0.27 volts. However, the side surface temperature, located in the same position, yielded lower results than the upper surface. It is crucial to incorporate a device for converting thermoelectric energy into voltage, necessitating a shallow placement of the thermoelectric device near the high-temperature, well-tempered concrete pavement surface to ensure efficient energy harvesting.

Heat-powered IoT node: A synergistic fusion of thermoacoustic engine and triboelectric nanogenerator

This study presents the design and analysis of a thermal energy harvester that integrates a thermoacoustic engine (TAE) with a honeycomb-structured triboelectric nanogenerator (H-TENG), referred to as TAEH-TENG. This design is specifically developed to demonstrate the potential of thermal energy harvesting for low-power Internet of Things (IoT) applications. By leveraging the high energy conversion efficiency of TAEs and the exceptional robustness of H-TENGs, this harvester overcomes the limitations of traditional designs, which often involve complex or costly components. The experimental results revealed the oscillation characteristics of the TAEH-TENG: by utilizing a hot heat exchanger (HHE) with a length of 10 cm, the system can sustain oscillation over 150–350 °C. Furthermore, the harvester is capable of generating an open-circuit voltage of 25 V, an RMS current of 0.98 μA, and a peak power output of 0.48 mW, representing the highest power output achieved to date in comparison to previous studies. To further showcase the harvester's capability, an ultra-low-power IoT node was developed. Solely powered by the TAEH-TENG, the IoT node achieved cold-start, conducted in situ temperature measurement five times, and transmitted the data via Bluetooth within 120 s. This study not only showcases a fully self-powered IoT application but, more importantly, significantly advances the technology beyond the previous limitations faced by thermoacoustic and triboelectric integrations. By demonstrating the capability to power an ultra-low-power IoT node, this research highlights the TAEH-TENG's potential for practical, real-world energy solutions, marking a significant milestone in the deployment of heat-powered IoT applications.

Clay-based anion-selective 2D nanofluidics boost natural osmotic power generation

Two-dimensional (2D) nanofluidics technology has shown great potential in efficient osmotic energy harvesting, while the lack of anion-selective 2D nanofluidics limits the development of full concentration cells towards real-world applications....

Simulation of Flax Threshing Process by Different Forms of Threshing Drums in Combined Harvesting

Flax, an important oil and fiber crop, is widely cultivated in temperate and sub-frigid regions worldwide. China is one of the major producers of flax, with Gansu Province predominantly practicing cultivation in hilly areas. However, common issues such as feeding difficulties, stem entanglement, and low threshing efficiency significantly restrict the improvement of planting efficiency. This study addresses the key technical challenges in flax combine harvesting in hilly regions by developing a discrete element model of the flax plant and utilizing DEM-FEA co-simulation technology. The performance of two threshing drum models (T1 and T2) was analyzed, focusing on motion trajectory, stress distribution, and threshing effects. The simulation results show that the T2 model, with its combination of rib and rod tooth design, significantly improves threshing and separation efficiency. The loss rate was reduced from 5.6% in the T1 model to 1.78% in the T2 model, while the maximum stress and deformation were significantly lower, indicating higher structural stability and durability. Field validation results revealed that the T1 model had a total loss rate of 3.32%, an impurity rate of 3.57%, and an efficiency of 0.09 hm2/h. In contrast, the T2 model achieved a total loss rate of 2.29%, an impurity rate of 3.39%, and an efficiency of 0.22 hm2/h, representing a 144.4% improvement in working efficiency. These findings indicate that the T2 model has a higher potential for flax harvesting in hilly and mountainous regions, especially in improving threshing efficiency and operational stability, providing an important theoretical basis for optimizing threshing equipment design.

Aproveitamento de águas pluviais

This work intends to develop a methodology to evaluate the potential of rainwater harvesting in the context of Aeronautics Command plants. From the case study of the Aeronautical Material Park of Galeão, it was possible to discuss the efficiency of pretreatment in improving the rainwater quality, create design parameters, improve technical design and analyze the technical and economic feasibility of rainwater harvesting in this military organization. Thus, it is expected that this methodology will serve as input for the development of projects in this area, enabling the achievement of a sustainable mindset and a reduction of Union expenses.

Self-Healing 2D Anion-Organic Frameworks for Low-Temperature Water Release.

Molecular frameworks have recently shown a great potential in atmospheric water harvesting, in which the water release at low temperatures is challenging. Anion-organic frameworks based on anion-coordination chemistry are presented herein to meet this challenge. These frameworks are prepared as tubular single crystals in pure water from the in-situ protonation and crystallization of pyridine-terminated triphenylamine derivatives with hydrochloric or hydrobromic acid. They possess a 2D honeycombed porous structure and carry halogen anions confined within 1D hexagonal nanochannels with a modular size of 1.7~2.3 nm. They exhibit a high water uptake of up to 0.87 g g-1 and a water release onset temperature as low as -90 oC. The water uptake and release induce significant changes in the crystal morphology and absorption and emission properties of these framework crystals, providing a visual indication of their hydration states over a wide temperature range. The kinetics of dehydration at subglacial temperatures is successfully determined by emission spectral shifts. These framework crystals show a high water-stability and can be used for repeated water capture and release thanks to a rapid and robust self-healing capability. This discovery opens opportunities for the design and synthesis of flexible and self-healing frameworks for porosity-related applications.

A Triboelectric Nanogenerator Utilizing a Crank-Rocker Mechanism Combined with a Spring Cantilever Structure for Efficient Energy Harvesting and Self-Powered Sensing Applications

With the advancement of industrial automation, vibrational energy generated by machinery during operation is often underutilized. Developing efficient devices for vibration energy harvesting is thus essential. Triboelectric nanogenerators (TENGs) based on spring and cantilever beam structures show considerable potential for industrial vibration energy harvesting; however, traditional designs often fail to fully harness vibrational energy due to their structural limitations. This study proposes a triboelectric nanogenerator (TENG) based on a crank-rocker mechanism and a spring cantilever structure (CR-SC TENG), which combines a crank-rocker mechanism with a spring cantilever structure, designed for both energy harvesting and self-powered sensing. The CR-SC TENG incorporates a spring cantilever beam, a crank-rocker mechanism, and lever amplification principles, enabling it to respond sensitively to low-frequency, small-amplitude vibrations. Utilizing the crank-rocker and lever effects, this device significantly amplifies micro-amplitudes, enhancing energy capture efficiency and making it well suited for low-amplitude, complex industrial environments. Experimental results demonstrate that this design effectively amplifies micro-vibrations and markedly improves energy conversion efficiency within a frequency range of 1–35 Hz and an amplitude range of 1–3 mm. As a sensor, the CR-SC TENG’s dual-generation units produce output signals that precisely reflect vibration frequencies, making it suitable for the intelligent monitoring of industrial equipment. When placed on an air compressor operating at 25 Hz, the first-generation unit achieved an output voltage of 150 V and a current of 8 μA, while the second-generation unit produced an output voltage of 60 V and a current of 5 μA. These findings suggest that the CR-SC TENG, leveraging spring cantilever beams, crank-rocker mechanisms, and lever amplification, has significant potential for micro-amplitude energy harvesting and could play a key role in smart manufacturing, intelligent factories, and the Internet of Things.

Sanctuary for migrating and wintering waterfowl: Synthesis and insights for waterfowl management and conservation planning

AbstractWaterfowl use a diversity of resources (e.g., food, structure, sanctuary) to meet energetic, social, and other life‐history demands during the non‐breeding period. Waterfowl often seek areas with limited human disturbance (i.e., sanctuary) during autumn and winter when hunting seasons are open perhaps to reduce exposure to mortality risks, minimize energy expenditure, and increase foraging efficiency, all of which should enhance survival and subsequent fitness. Prior studies of sanctuary use by waterfowl have mostly focused on patterns of abundance and behavior, with many documenting differential diel movements of marked birds in and around sanctuaries. Although reduced mortality risk is likely associated with sanctuary use, much less is known about the potential effects on energy expenditure, body condition, reproductive consequences at the individual level, and seasonal distribution with respect to viewing and harvest potential. We consider these aforementioned factors among the most significant gaps in our understanding of the function of sanctuary in waterfowl management. As waterfowl hunter recruitment, retention, and reactivation have become a major initiative of many natural resource agencies and a core principle of the North American Waterfowl Management Plan, we discuss the potential role of sanctuary relative to these efforts. Herein, we review historical aspects of waterfowl sanctuary, introduce hypotheses about its potential role in habitat resource management and conservation planning during autumn and winter, discuss our knowledge of the effects of sanctuary on waterfowl, and share insights to inform decisions about the role of sanctuary in waterfowl management given currently available evidence and remaining uncertainties. Our review describes the existing evidence for the biological and social outcomes of sanctuary, draws some conclusions about the role of sanctuary in natural resource management given the available evidence, and outlines potential research opportunities to help us make informed decisions regarding sanctuary implementation for waterfowl.

Recent Developments in Electrospun Nanofiber-Based Triboelectric Nanogenerators: Materials, Structure, and Applications.

Triboelectric nanogenerators (TENGs) have garnered significant attention due to their high energy conversion efficiency and extensive application potential in energy harvesting and self-powered devices. Recent advancements in electrospun nanofibers, attributed to their outstanding mechanical properties and tailored surface characteristics, have meant that they can be used as a critical material for enhancing TENGs performance. This review provides a comprehensive overview of the developments in electrospun nanofiber-based TENGs. It begins with an exploration of the fundamental principles behind electrospinning and triboelectricity, followed by a detailed examination of the application and performance of various polymer materials, including poly (vinylidene fluoride) (PVDF), polyamide (PA), thermoplastic polyurethane (TPU), polyacrylonitrile (PAN), and other significant polymers. Furthermore, this review analyzes the influence of diverse structural designs-such as fiber architectures, bionic configurations, and multilayer structures-on the performance of TENGs. Applications across self-powered devices, environmental energy harvesting, and wearable technologies are discussed. The review concludes by highlighting current challenges and outlining future research directions, offering valuable insights for researchers and engineers in the field.

Vacancy engineering in tungsten oxide nanofluidic membranes for high-efficiency light-driven ion transport.

Bioinspired light-driven ion transport has shown great potential in solar energy harvesting. To achieve efficiencies comparable to biological counterparts, effective coregulation of permselectivity and photoresponsivity is crucial. Herein, vacancy engineering has been proven to be a powerful strategy for considerably increasing the efficiency of light-driven ion transport in tungsten oxide (WO3-x) nanofluidic membranes by enhancing the negative surface charges and narrowing bandgaps. The enhancement in light-driven ion transport can be attributed to the efficient redistribution of surface charges due to the effective separation of photogenerated carriers. At an optimized vacancy concentration, WO2.66 membrane (WO2.66M) delivers an ionic photocurrent of 0.8μAcm-2 in a 10-4M KCl electrolyte, which is four times higher than that generated by the original WO2.85 membrane (WO2.85M). Following this strategy, uphill ion transport and photoenhanced osmotic energy conversion are successfully achieved in the WO3-x nanofluidic membrane system. This study shows that atomic vacancy engineering is an efficient approach to increase the light-driven ion transport dynamics of nanofluidics, providing an efficient strategy to enhance light-driven ion transport for potential applications in power harvesting and ion separation.

Evaluating the Potential of Multitype Energy Harvesting in New Energy Vehicles: A Systematic Review and Quantitative Analysis

This review presents an overview in the context of the current state of the art in energy harvesting technologies for new energy vehicles (NEVs) and delves into the significant energy losses experienced by NEVs during driving, braking, and overcoming wind resistance. Based on the different forms of energy losses, the prevalent energy harvesting technologies in the NEV domain are elucidated, with a focus on the fundamental principles of vibration energy, braking energy, wind energy harvesting, and their recent advancements in practical implementations. Vibration energy harvesting involves the conversion of mechanical energy from the suspension system into electrical energy, while brake energy harvesting captures a portion of the brake friction loss as electrical energy during braking, and wind energy harvesting utilizes wind power generators on the vehicle surface to produce electricity. By quantitatively evaluating the recovery effects of different types of systems, the report demonstrates the great potential of energy harvesting technologies to improve energy efficiency and extend the range of NEVs. Furthermore, it explores the future trajectory of energy harvesting technology, envisioning its integration as a standard feature in NEVs and heralding transformative progress in the global energy and transportation sectors.

STONEHENGE – A toolbox for nonlinear vibration energy harvesting

In this work, we present STONEHENGE - Suite for nonlinear analysis of energy harvesting systems, a comprehensive toolbox engineered to study nonlinear piezoelectric vibration energy harvesters. These harvesters can harness kinetic energy from the environment and convert it into electricity using the piezoelectric effect. By introducing nonlinearity through strategically placed magnets, their efficiency is enhanced across a wide frequency spectrum. However, it comes at the cost of increasing complexity in system dynamics. To investigate this complexity and comprehend the potential of nonlinear energy harvesting, the STONEHENGE library was created. It is tailored to analyze the harvesting performance and dynamic behavior of these systems and allows users to explore and characterize system dynamics across a diverse range of physical parameters and excitation conditions using advanced numerical simulations. The toolbox encompasses six key modules, (i) initial value problem, analysis of system behavior from initial conditions; (ii) dynamic animation: which provides visual representations of system dynamics, aiding in intuitive understanding and interpretation; (iii) nonlinear tools: equips users with tools to dissect and comprehend the nonlinear aspects of vibration harvesting systems, essential for comprehensive analysis; (iv) sensitivity analysis: facilitates the assessment of how system behavior responds to variations in parameters, offering insights into its robustness and performance under different conditions; (v) stochastic simulation: allows for the exploration of system behavior under stochastic excitation, crucial for understanding real-world operating conditions; (vi) chaos control: offers methods for mitigating chaotic behavior within the system, enhancing predictability and stability. Utilizing a bistable oscillator as a benchmark, STONEHENGE aims to serve as a valuable resource for the development and refinement of both existing and emerging nonlinear vibration-based energy harvesting systems. By providing a comprehensive toolkit for analysis and characterization, STONEHENGE seeks to catalyze advancements in this field, ushering in an era of more efficient and sustainable energy harvesting technologies. Moreover, this library was developed to be easily adaptable to different dynamic systems and can contribute to different application fields.

Four-dimensional flow characteristics of air-entrained turbulent impinging waterjet onto quiescent water surface

This paper presents a time-resolved three-dimensional (4D) flow fields measurement of the continuous phase of a turbulent impinging jet inducing foam formation using the Lagrangian particle tracking velocimetry utilizing the Shake-The-Box algorithm. With the systems equipped with four high-speed cameras, time-series of images of fluid tracer particles were acquired. The Vortex-In-Sharp (VIC#) method was used to reconstruct the Eulerian flow fields of the particle tracks. The impinging jet was characterized as plume-like along the vertical direction with two distinct layers: developing shear and fully developed shear. The streamwise vortex structures of the continuous phase were influenced by the bubble plume motion, and the results showed high amplitude oscillations of the acceleration and deceleration near the jet source resulting in the formation of ring-like vortices, which break down as the jet moves downstream with its momentum dissipated. The flow of the continuous phase of impinging jet was self-similar both at the developed shear layer and the fully developed diffusion layer beneath the water pool and is characterized as homogeneous shear flow with anisotropy turbulence. The classical assumption of self-similarity with Gaussian profiles for continuous phase velocity is verified experimentally. We found that the results show a huge potential of blue energy harvesting from the low frequency (∼2 Hz) dissipating kinetic energy of the turbulent plume-like jet underneath the impinging water surface using triboelectric nanogenerator.

Biopolymeric Ionotronics Based on Biodegradable Wool Keratin.

The advent of ionotronics has revealed significant potential in flexible transistors, energy harvesting, and unconventional circuits. However, most ionotronic devices, often centered around synthetic polymers, involve complex grafting or synthesis that raise legitimate concerns about their environmental sustainability. Herein, a simple yet versatile approach for developing single-composition ionotronic devices using wool keratin (WK), a biodegradable and pH-responsive natural polymer is presented. By employing facile pH regulation processes, WK molecules with opposing polarities are successfully modified, which are combined to form an ionic heterojunction through entropically driven depletion. This ionic heterojunction functions as an ionic diode, enabling efficient rectification of alternating current signals (with a rectification ratio of up to 199). Furthermore, the application of this biopolymeric ionotronic device is extended to mechanical energy harvesting, self-powered sensing, and ionic logic circuit. The biodegradability and renewability of WK offer a viable alternative to synthetic materials, highlighting its potential for sustainable applications.

Boosted triboelectric performance in stretchable nanogenerators via 2D MXene-Driven electron accumulation and LiNbO₃-assisted charge transfer

The development of piezoelectrically enhanced triboelectric hybrid nanogenerators (PET-HNGs) has garnered considerable attention for their potential in energy harvesting. However, their performance in stretchable applications across diverse environments, such as air and water, remains limited due to the lack of high-performance, stretchable material compositions and a comprehensive understanding of the charge transfer mechanism involved. To address these challenges, we have designed a high-performance, stretchable nano-/micro-composite film by embedding 2D MXene nanosheets and piezoelectric LiNbO3 microparticles into an Ecoflex polymer matrix. Quantum mechanical calculations revealed that MXene nanosheets significantly increase electron density near the Fermi level, while LiNbO3 microparticles enhance electron transfer during contact electrification with polydimethylsiloxane (PDMS). This synergistic effect resulted in a substantial enhancement of the triboelectric energy harvesting performance, with the composite film exhibiting a 355 % increase in voltage, a 324 % increase in current, and a 100 % boost in power output density compared to systems using pure Ecoflex based TENGs. The fabricated PET-HNG demonstrated remarkable output metrics, including a voltage of 455 V, current of 140 μA, power output density of 15.6 W m−2, and an energy conversion efficiency of 78.5 %, all while maintaining exceptional performance stability even under mechanical stretching.This stretchable nanogenerator shows great potential as a self-powered wearable sensor for real-time biomechanical monitoring in various environments, including air and underwater. This innovation paves the way for the development of next-generation wearable electronics and energy harvesting devices.

Innovative Strategy for Rainwater Harvesting in Saline-affected Urban Areas: A Case Study of a Sports Complex in Delhi

Water scarcity remains a critical global challenge, requiring immediate, sustainable management strategies, particularly in areas with an increasing disparity between water supply and demand. In India, and especially in Delhi, this issue is acute. In response to growing environmental concerns and the urgent need for sustainable water resource management, rainwater harvesting has emerged as a practical and effective solution for water conservation. This study investigates the application of rainwater harvesting to sustainably support water needs for a sports complex located in a salinity affected region. The land, originally intended for agriculture, has been converted into a complex featuring hydro-landscape facilities, including swimming pools, water polo areas, diving pools, toddler pools, and leisure pools. These facilities require an initial water input of 6,754.5 m³ and an annual replenishment of 7,957.28 m³ due to evaporation and seepage. By calculating the total rainwater harvesting potential based on the runoff coefficient, annual rainfall intensity, and the complex's catchment area, the study reveals that 29,693.8 m³ of rainwater can be harvested annually, providing a surplus of 14,981.7 m³ of potable water. This analysis demonstrates the viability of designing sports complexes in saline areas using efficient land use and rainwater harvesting, and presenting a scalable model for sustainable water management in similar regions worldwide.

Giant piezoelectricity in fluoropolymer fiber mats achieved by corona poling in water

Polymer piezoelectrics hold great potential for energy harvesting and wearable electronics. Efforts have been dedicated to enhancing piezoelectric coefficients and thermostability for several decades, but most of these have not been successful. In this report, we demonstrate a straightforward way to achieve high piezoelectric coefficients and output voltages while maintaining high thermostability at temperatures over 110 °C. Poly(vinylidene fluoride-co-trifluoroethylene) [P(VDF-TrFE)] 80/20 mol.% nanofiber mats (made by electrospinning) with extremely high crystallinity and Curie temperatures were obtained via a two-step annealing process, from which large ferroelectric domains were formed in extended-chain crystals. After corona poling using water, which is a high dielectric constant medium, giant piezoelectricity (apparent d33 = 1045 ± 20 pC/N) and high output voltages (29.9 ± 0.5 V) were achieved. It is found that the dimensional effect induced significant polarization changes, which is the key requirement for piezoelectricity. Our finding in this work paves a way to further improve high-performance polymer piezoelectrics.

Photovoltaic Integrated Shading Devices in the Retrofitting of Existing Buildings on Chinese Campuses Within a Regional Context

Retrofitting existing buildings to be more energy-efficient is a tremendous contribution to the sustainability of society. The application of photovoltaic integrated shading devices (PVSDs) accords with this ambition by blocking out unwanted radiant heat gain and generating clean electricity. The deployment of PVSDs needs sensible design strategies to optimize the production of renewable energy while retaining the aesthetic quality of the built-up environment, especially in historic campuses. The concept was tested in a case study of buildings in South China University of Technology (SCUT) using Ladybug 1.4.0 and PVsyst 7.2, utilizing the existing “Xia’s shading” design method in historical environments and optimizing the design from the perspective of photovoltaic performance. Firstly, the photovoltaic (PV) panels were integrated as architectural components, and the parameters were incorporated into a mathematical equation based on “Xia’s shading” design method. This was followed by the assessment of the solar energy harvesting potential based on simulated annual solar irradiation values. Lastly, the PV panels’ solar irradiation potential under these different parameters was shown in figures to identify the optimum parameters combination for PVSD applications. The proposed methodology could evolve as a design tool and thus further assist in promoting the large-scale adoption of PVSDs in retrofit projects.

Industrial production of asymmetric wettability patterned fabric for efficient atmospheric water harvesting

While harvesting water from the atmosphere is considered as a promising technology to address the increasing issue of water scarcity, its wide applications are still limited by the difficulty in mass production of water harvesting materials. Here, an industrial-producible asymmetric wettability patterned fabric (AWPF) with high water harvesting capacity is developed using a continuous and low-cost weaving technology. Four textile patterns are developed for high-efficiency atmospheric water harvesting. The alternating patterned surface in AWPF is constructed with hydrophilic bumps and hydrophobic grooves using one set of green fluorine-free superhydrophobic polyester warp yarns and two sets of superhydrophobic polyester/hydrophilic viscose weft yarns. We optimized the water collection performance of the single-sided AWPF by spraying co-MBAA-DVB superhydrophobic material on the back of the AWPF to construct a wetting gradient, that is, double-sided AWPF. The double-sided AWPF shows a strong water harvesting capacity of 2840.2 mg·6h−1·cm−2, which increased the water harvesting efficiency by 43.2 % compared with the unoptimized single-sided AWPF. To reduce the pressure drop, 6 mm wide the double-sided AWPF was designed, resulting in a water harvesting capacity that is 1.23 times higher than that of without cutting. This advanced industrialized weaving technology with an asymmetric fabric structure design holds great potential for substantial water harvesting.

Nanoarchitecture via Synchronic Stacking of Metallic and Nonmetallic Two-Dimensional Nanosheets for Optimal Light-Driven Ion Transport.

The exceptional selectivity and responsive ion transport in biological channels inspire technology breakthrough in energy, environmental, and resource sectors. However, existing nanofluidic systems with a high photothermal conversion efficiency often exhibit excessive thermal conductivity, which impedes the creation of effective temperature gradients and results in a low ion transport efficiency. In this study, a strategy based on the synchronic stacking of metallic and nonmetallic two-dimensional (2D) nanosheets was presented to construct heterogeneous nanofluidic channels. This specific nanoconfined architecture sustained high temperatures in the illuminated area while maintaining low temperatures in the nonilluminated area, thus obtaining a robust driving force from sunlight for directional ion transport. As a result, our light-responsive ion transport system demonstrated significant potential in solar energy conversion and osmotic energy harvesting, surpassing those of all previously reported nanofluidic systems. Additionally, although it is still at the proof-of-concept stage, it shows great promise in light signal monitoring. This work provides an effective strategy for developing advanced light-responsive ion transport systems and their important applications.