Harvesting Technology Research Articles

Macroscopic liquid superlubric triboelectric nanogenerator: An in-depth understanding of solid-liquid interfacial charge behavior

Triboelectric nanogenerator (TENG) has been seen as one of the most promising energy harvesting technologies. However, there are an irreconcilable contradiction between low friction and high electrical output performance of the TENG. Here, we have devised a macroscale liquid superlubric triboelectric nanogenerator based on solid-liquid-solid structure, leveraging the concept of liquid superlubricity technology, resulting in a remarkable increase in both the open circuit voltage and short-circuit current by 53.0 % and 58.4 %, respectively. This huge increase in electrical output performance is accompanied by a 99.1 % reduction in friction coefficient (≈ 0.0025) and 99.993 % reduction in wear rate (≈ 0.76×10−7 mm3/N·m), when compared to those of a lubricant-free triboelectric nanogenerator. This work delves into the lubrication and charge transfer mechanisms. The liquid superlubricity technology achieves friction reduction through a hybrid mechanism combining boundary and hydrodynamic lubrication. And the high outputs arise from the charges transfer at solid-liquid interface. The triboelectric charges generated by the friction pair are transferred from solid to the lubricating liquid. Meanwhile, the lubricating liquid promotes electron transfer and contributes additional electrons. Our work provides profound insights into the lubrication and charge transfer mechanisms at solid-liquid interfaces, and addresses the paradox of high output and low friction in TENGs.

Особенности эксплуатации лесовозных дорог в весенне-зимний период

Seasonal roads are not capital construction objects. Unlike all-season ones, they can be of summer and winter action. During the transport development of forests, both allseason paved roads and temporary unpaved roads are required. The share of temporary roads is more than 90 % of all logging roads. One of the main problems of temporary logging roads is uneven seasonal operation, especially in summer. Seasonal roads do not have a permanent surface; more often it is natural soil, subject, except for mechanical impacts, to atmospheric ones, which is most evident in the summer-autumn period. Therefore, about 80 % of the harvested wood is exported via winter roads. The density of temporary roads depends on the general harvesting technology in a particular area, including the wood skidding distance and the angle of relative position of forest roads. Winter road construction works are carried out in summer and winter. In summer, engineering surveys are carried out, the optimal direction of the future route is determined, a clearing is cut, a roadbed is prepared, and if necessary, culverts are installed. With the onset of cold weather, the existing soil is compacted and leveled to accelerate its freezing. If the roadbed is sufficiently frozen, a snow-ice cover is formed. The article considers the influence of roadside forest plantations on the air temperature near the road surface, soil temperature, blocking solar radiation – the factors that are directly related to the overall service life of a winter road. Special attention is paid to slowing down the decrease in the winter road pavement strength in the shade of preserved trees by choosing the optimal route direction. The slowdown in the decrease in the pavement strength of the forest dirt road has been established and confirmed in areas where solar radiation is blocked by trees, i.e. in the shade. The difference in strength reduction to the minimum is 33 days. Based on the research results, it has been concluded that a comprehensive development of the logistics strategy for the organization of roundwood transportation via winter roads is necessary.

Active reallocation of photogenerated carriers by triboelectric electro-field for improving nonuniformly illuminated photovoltaic module

Different from standard indoor testing for photovoltaic (PV) cells, the outdoor working of large PV modules suffers an inevitable issue of nonuniform illumination. Even a 10 % partial area shading results in an 80 % power attenuation. This can be attributed to the endogenous lateral transfer of photogenerated carriers between differently illuminated zones. Herein, we presented an active reallocation strategy for rationalizing lateral carrier transfer inside PV modules, which utilizes triboelectric electro-field to dynamically balance the p-n junction barrier height at interfaces of different illumination states. As demonstrated by a flexible hybrid energy harvester combining triboelectric nanogenerators (TENGs) and solar cells, by managing with rectifier-free circuits or even small chips, a small power sacrifice of TENGs exchanges for remarkable performance improvement of PV modules, leading to a power output gain of up to 87.7 % for half-shaded PV modules of different material and structural configurations. Besides, the reallocation electric field adapts well to a wide range of voltage or even pulsed triboelectric voltage, providing a mutually beneficial energy management technology for multi-source energy harvesting. This strategy of active reallocation by triboelectric effect provides an endogenous PV module promotion approach with prominent structural adaptability for distributed or even portable on-body power generation.

Shear Thickening Fluid and Sponge-Hybrid Triboelectric Nanogenerator for a Motion Sensor Array-Based Lying State Detection System.

Issues of size and power consumption in IoT devices can be addressed through triboelectricity-driven energy harvesting technology, which generates electrical signals without external power sources or batteries. This technology significantly reduces the complexity of devices, enhances installation flexibility, and minimizes power consumption. By utilizing shear thickening fluid (STF), which exhibits variable viscosity upon external impact, the sensitivity of triboelectric nanogenerator (TENG)-based sensors can be adjusted. For this study, the highest electrical outputs of STF and sponge-hybrid TENG (SSH-TENG) devices under various input forces and frequencies were generated with an open-circuit voltage (VOC) of 98 V and a short-circuit current (ISC) of 4.5 µA. The maximum power density was confirmed to be 0.853 mW/m2 at a load resistance of 30 MΩ. Additionally, a lying state detection system for use in medical settings was implemented using SSH-TENG as a hybrid triboelectric motion sensor (HTMS). Each unit of a 3 × 2 HTMS array, connected to a half-wave rectifier and 1 MΩ parallel resistor, was interfaced with an MCU. Real-time detection of the patient's condition through the HTMS array could enable the early identification of hazardous situations and alerts. The proposed HTMS continuously monitors the patient's movements, promptly identifying areas prone to pressure ulcers, thus effectively contributing to pressure ulcer prevention.

Triboelectric Series of Two‐dimensional Metal Carbide MXenes

AbstractThe ever‐increasing prevalence of intelligent electronics underscores an escalating demand for sustainable power sources. Among the emerging energy harvesting technologies, triboelectric nanogenerators (TENGs) stand out as a promising solution for such pressing needs. To date, ongoing efforts have primarily focused on enhancing TENG output, particularly through the development of novel triboelectric materials. Among the potential candidates is the thriving class of two‐dimensional transition‐metal carbides, MXenes, which have predominantly been incorporated into triboelectric layers as nanofillers to enhance their triboelectric properties. Yet, the specific triboelectric characteristics of distinct MXenes remain marginally explored. Herein, the triboelectric properties of various metal carbide MXenes, i.e., V2CTx, Ti3C2Tx, and Nb2CTx, are investigated by assessing the performance of various MXene‐based TENGs combined with different polymers and analyzing their surface potential. According to the attained triboelectric polarities, a triboelectric series of the studied MXenes is determined, demonstrating their remarkable positive triboelectric properties. Further investigations preliminarily reveal the influence of the synthesis method, etchants, intercalating compounds, and postsynthesis procedures on the triboelectric properties of MXenes. Hence, beyond extending the conventional triboelectric series to different metal carbide MXenes, the findings present innovative perspectives on leveraging MXenes to develop high‐performance TENGs for flexible and wearable electronics.

Assessing soil degradation in Brazilian agriculture by a remote sensing approach to monitor bare soil frequency: impact on soil carbon

In countries with extensive agricultural practices, there is a significant risk of soil degradation, making it essential to develop techniques for understanding and detecting these changes. In this study, we used an earth observation system to identify the temporal bare soil frequency and thus, relate it with soil tillage and its impact on soil carbon degradation. The work was performed in two important agricultural states of Brazil, São Paulo and Paraná. For that, historical field and Remote Sensing (RS) data were analyzed to identify the relation between bare soil areas and their degradation. The frequency of bare soil was detected by Landsat images, in the last 36 years using the Geospatial Soil Sensing System (GEOS3). Historical soil surface temperature data was produced using the same images. In addition, legacy pedological and crops (i.e., soil cover) maps were used. Finally, soil texture information was spatialized based on a synthetic soil image (SISY). A total of 28,000 sites with topsoil organic carbon (SOC) were used as the reference for degradation. The soils of the state of Paraná presented significantly lower bare soil areas when compared to the state of São Paulo, mainly due to the wide use of the No-Tillage system. The advancement of sugarcane harvesting technologies together with the "boom" of the commodities after 2000s was responsible for the considerable increases in soil cover conservation. It was noticed that the more exposed the soil remains, the less carbon it has, having a negative correlation (r≈ −0.5). Sandy soils in both states proved to be the ones that were subject to the highest exposure rates and thus, more degraded. This fact is of concern, given that sandy soils are more susceptible to degradation factors, such as erosion. We observed important historical public policies related to the temporal tillage systems adopted by agro-community, which had a significant impact on carbon dynamics. The remote technique was able to infer how the soil has been managed. This information is crucial as it provides a solid basis for developing future public policies aimed at sustainable production.

Conceptualization, design, and construction of a novel insect mass trapping device: the USDA Biomass Harvest Trap (USDA-BHT).

The use of insects as animal feed has the potential to be a green revolution for animal agriculture as insects are a rich source of high-quality protein. Insect farming must overcome challenges such as product affordability and scalability before it can be widely incorporated as animal feed. An alternative is to harvest insect pests from the environment using mass trapping devices and use them as animal feed. For example, intensive agricultural environments generate large quantities of pestiferous insects and with the right harvest technologies, these insects can be used as a protein supplement in traditional animal daily rations. Most insect trapping devices are limited by the biomass they can collect. In that context, and with the goal of using wild collected insects as animal feed, the United States Department of Agriculture-Biomass Harvest Trap (USDA-BHT) was designed and built. The USDA-BHT is a valuable mass trapping device developed to efficiently attract, harvest, and store flying insects from naturally abundant agricultural settings. The trap offers a modular design with adjustable capabilities, and it is an inexpensive device that can easily be built with commonly available parts and tools. The USDA-BHT is also user-friendly and has customizable attractants to target various pest species.

Harvesting insect pests for animal feed: potential to capture an unexploited resource.

The demand for animal protein grows as the human population increases. Technological and genetic advances in traditional animal agriculture will not produce enough protein to meet future needs without significant innovations such as the use of insects as protein sources. Insect farming is growing insects, whereas insect harvesting is collecting insects from their natural habitats to produce high-quality protein for animal feed or human food. Intensive agricultural environments produce tremendous quantities of pestiferous insects and with the right harvest technologies these insects can be used as a protein supplement in traditional animal daily rations. An avenue to exploit these insects is to use traps such as the United States Department of Agriculture-Biomass Harvest Trap (USDA-BHT) to efficiently attract, harvest, and store insects from naturally abundant agricultural settings. The modular design allows for a low cost, easy to build and fix device that is user friendly and has customizable attractants to target various pest species. Although insect harvesting faces substantial challenges, including insect biomass quantity, seasonal abundance and preservation, food safety, and economic and nutritional evaluation, the potential for utilizing these pests for protein shows tremendous promise. In this forum, insect harvesting is discussed, including its potential, limitations, challenges, and research needs. In addition, the use of a mass trapping device is discussed as a tool to increase the biomass of insects collected from the environment.

Advances in Energy Harvesting Technologies for Wearable Devices.

The development of wearable electronics is revolutionizing human health monitoring, intelligent robotics, and informatics. Yet the reliance on traditional batteries limits their wearability, user comfort, and continuous use. Energy harvesting technologies offer a promising power solution by converting ambient energy from the human body or surrounding environment into electrical power. Despite their potential, current studies often focus on individual modules under specific conditions, which limits practical applicability in diverse real-world environments. Here, this review highlights the recent progress, potential, and technological challenges in energy harvesting technology and accompanying technologies to construct a practical powering module, including power management and energy storage devices for wearable device developments. Also, this paper offers perspectives on designing next-generation wearable soft electronics that enhance quality of life and foster broader adoption in various aspects of daily life.

Optimized Energy Efficient- Hierarchical Clustering Based Routing (OEE-HCR) For Wireless Sensor Network (WSN)

The study into Wireless Sensor Network (WSN) has grown more crucial as a result of the many Internet of Things (IoT) applications. Energy – Harvesting (EH) technology can extend the lifespan of WSN; however, because the nodes would be difficult to get to during energy harvesting, an energy-efficient routing protocol should be developed. The use of clustering in this study balances energy consumption across all Sensor Node (SN) and reduces traffic and overhead throughout the data transmission phases of WSN. Cluster Head (CH) selection step of the Optimized Energy Efficient-Hierarchical Clustering Based Routing (OEE-HCR) technique involves sending data to the closest CH. In order to analyse and transmit each cluster data, CH will need to use more energy, which will hasten and asymmetrically deplete the network. Whale Optimization Algorithm (WOA) algorithm is introduced for the best number of clusters formation with dynamically selecting the CH. Experimentation analysis, results are measured using First Node Dead (FND), the Half Node Dead (HND), Last Node Dead (LND), and Maximum Lifetime Coverage (MLC) at the time of number of data transmission rounds performed in routing algorithms.

Triboelectric Nanogenerators: State of the Art.

The triboelectric nanogenerator (TENG), as a novel energy harvesting technology, has garnered widespread attention. As a relatively young field in nanogenerator research, investigations into various aspects of the TENG are still ongoing. This review summarizes the development and dissemination of the fundamental principles of triboelectricity generation. It outlines the evolution of triboelectricity principles, ranging from the fabrication of the first TENG to the selection of triboelectric materials and the confirmation of the electron cloud overlapping model. Furthermore, recent advancements in TENG application scenarios are discussed from four perspectives, along with the research progress in performance optimization through three primary approaches, highlighting their respective strengths and limitations. Finally, the paper addresses the major challenges hindering the practical application and widespread adoption of TENGs, while also providing insights into future developments. With continued research on the TENG, it is expected that these challenges can be overcome, paving the way for its extensive utilization in various real-world scenarios.

Beyond Metallic Electrode: Spontaneous Formation of Fluidic Electrodes from Operational Liquid in Highly Functional Droplet-Based Electricity Generator.

The droplet-based electricity generator (DEG) has facilitated efficient droplet energy harvesting, yet diversifying its applications necessitates the incorporation of various to the DEG. This study first proposes a methodology for advancing the DEG by substituting its conventional metallic electrode with electrically conductive water electrode(WE), which is spontaneously generated during the operation of the DEG with operating liquid. Due to the inherent conductive and fluidic nature of water, the introduction of the WEmaintains the electrical output performance of the DEG while imparting functionalities such as high transparency and flexibility. So, the resultant WEapplied DEG (WE-DEG) exhibits high optical transmittance (≈99%) and retains its electricity-generating capability under varying deformations, including bending and stretching. This innovation expands the versatility of the DEG, and especially, a sun-raindrop dual-mode energy harvester is demonstrated by hybridizing the WE-DEG and photovoltaic (PV) cell. This hybridization effectively addresses the weather-dependent limitations inherent in each energy harvester and enhances the temperature-induced inefficiencies typically observed in PV cells, thereby enhancing the overall efficiency. The introduction of the WEwill be poised to catalyze new developments in DEG research, paving the way for broader applicability and enhanced efficiency in droplet energy harvesting technologies.

Green Synthesis of Polyurethane Sponge-Grafted Calcium Alginate with Carbon Ink Aerogel with High Water Vapor Harvesting Capacity for Solar-Driven All-Weather Atmospheric Water Harvesting.

Atmospheric water harvesting (AWH) technology is a new strategy for alleviating freshwater scarcity. Adsorbent materials with high hygroscopicity and high photothermal conversion efficiency are the key to AWH technology. Hence, in this study, a simple and large-scale preparation for a hygroscopic compound of polyurethane (PU) sponge-grafted calcium alginate (CA) with carbon ink (SCAC) was developed. The PU sponge in the SCAC aerogel acts as a substrate, CA as a moisture adsorber, and carbon ink as a light adsorber. The SCAC aerogel exhibits excellent water absorption of 0.555-1.40 g·g-1 within a wide range of relative humidity (40-80%) at 25 °C. The SCAC aerogel could release adsorbed water driven by solar energy, and more than 92.17% of the adsorbed water could be rapidly released over a wide solar intensity range of 1.0-2.0 sun. In an outdoor experiment, 57.517 g of SCAC was able to collect 32.8 g of clean water in 6 h, and the water quality meets the drinking water standards set by the World Health Organization. This study suggests a new approach to design promising AWH materials and infers the potential practical application of SCAC aerogel-based adsorbents.

Advancements in Energy Harvesting: Piezoelectric, Triboelectric, Pyroelectric, and Magnetoelectric Technologies for Self-powered Sensor Systems

In the era of Internet of Things (IoT) advancements, millions of sensors and electronic devices are interconnected through the internet. A reliable power source is required for their continuous operation. Self-powered sensor systems have emerged as promising solutions for various applications including wearable devices and environmental monitoring, benefiting both society and the environment. These systems can maintain themselves by eliminating the need for external power sources or frequent battery replacements and converting discarded energy sources around them into electrical energy. Among various energy harvesting technologies, piezoelectric, triboelectric, pyroelectric, and magnetoelectric mechanisms have garnered significant attention due to their ability to convert mechanical, frictional, thermal, and magnetic energy into electrical power, respectively. This review aims to provide a comprehensive overview of recent advances in these technologies for self-powered sensor systems, catering to a wide audience. It explores fundamental principles of their-energy harvesting mechanisms, highlighting their strengths, limitations, and potential applications. In addition, this review discusses challenges related to the development of nanogenerator-based self-powered sensor systems and presents new opportunities for their advancement.

Enhancing β-phase and dielectric properties of BCZT lead-free reinforced in PVDF-HFP composite thick films for eco-friendly energy harvesting

Barium titanate doped with calcium and zirconium (BCZT) relaxor ferroelectric ceramics enhance energy storage capabilities due to their excellent ferroelectric and dielectric properties. In this investigation, BCZT particles (Ps) were incorporated into poly (vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) using the solvent casting method to prepare biocompatible composite films with varying BCZT Ps contents. The uniform dispersion and distribution of BCZT Ps throughout the polymer matrix results in robust interfacial interactions, promoting improved nucleation of the β-phase in PVDF-HFP and increased thermal stability with higher BCZT Ps loading. The Young's modulus and tensile strength of the composites experienced respective increases of 78.2 % and 41.8 % with the addition of 20 wt% BCZT Ps. While the dielectric constant was improved from 12 to 31. This research contributes to the development of flexible composite films with different BCZT Ps contents, to promote an innovative and environmentally friendly energy harvesting technology. This innovation captures environmental vibrations and converts them into electrical energy to supply a variety of sensors.

3D Bionic Water Harvesting System for Efficient Fog Capturing and Transporting

AbstractFog harvest has emerged as a direct and efficient water harvesting technology to relieve the intense pressure of freshwater scarcity worldwide. With the vagaries of climate and increasing amount of energy consumption, high‐efficiency fog harvest devices focus on the fast water droplet capture and transportation are highly desired. In this study, a novel harp structure is developed using cross‐twisted copper filaments arranged in a spatial triangular pattern to enhance water droplet capture and transportation. Inspired by the natural differences in Laplace pressure observed in cactus and spider silks, this design accelerates the movement of water bridges. Besides, drawing on the fruit waxes on the surface of hogweed and blueberries, a paraffin wax coating is applied on the copper sheet frame to create a solid slip frame, improving the synergy between filament capture and frame transportation. The monolithic fog collector (MFC) thus achieves a significant increase in fog harvest efficiency and demonstrates excellent durability. Integration of the MFCs into a 3D high‐efficiency fog harvest system results in a harvest rate of 0.5027 g cm−2 min−1, showing promise for practical applications due to its durability, simplicity, and environmental friendliness.

3D-printed Bi2Te3-based Thermoelectric Generators for Energy Harvesting and Temperature Response.

Thermoelectric generators (TEGs) are environmentally friendly energy harvesting technologies that hold great promise in the field of self-powered electronics and sensing. However, the current development of thermoelectric (TE) devices has largely lagged behind the development of thermoelectric materials, especially in the preparation of thermoelectric components with customizable shapes and excellent properties, which largely limits their practical applications. These issues can be effectively addressed by using 3D printing technology. Here, we print multiple p-type thermoelectric legs (pins) consecutively with this simple technique, and the printed TEGs have excellent thermal potential (288 μV K-1 at room temperature) and excellent temperature response properties, which exhibited an output voltage of 127.94 mV at a temperature difference (ΔT) of 40 K. The 3D-printed thermoelectric generator enables the collection of thermal energy. In addition, the device has excellent temperature sensing characteristics, and this temperature signal to electrical signal conversion is very rapid, which enables temperature sensing alarms in a wide temperature domain. Combining these features, an energy harvesting and electrical alarm concept for home-scale applications is proposed, which is expected to provide a diverse research idea for the application of next-generation thermoelectric devices.

Advanced Energy Harvesters and Energy Storage for Powering Wearable and Implantable Medical Devices.

Wearable and implantable active medical devices (WIMDs) are transformative solutions for improving healthcare, offering continuous health monitoring, early disease detection, targeted treatments, personalized medicine, and connected health capabilities. Commercialized WIMDs use primary or rechargeable batteries to power their sensing, actuation, stimulation, and communication functions, and periodic battery replacements of implanted active medical devices pose major risks of surgical infections or inconvenience to users. Addressing the energy source challenge is critical for meeting the growing demand of the WIMD market that is reaching valuations in the tens of billions of dollars. This review critically assesses the recent advances in energy harvesting and storage technologies that can potentially eliminate the need for battery replacements. With a key focus on advanced materials that can enable energy harvesters to meet the energy needs of WIMDs, this review examines the crucial roles of advanced materials in improving the efficiencies of energy harvesters, wireless charging, and energy storage devices. This review concludes by highlighting the key challenges and opportunities in advanced materials necessary to achieve the vision of self-powered wearable and implantable active medical devices, eliminating the risks associated with surgical battery replacement and the inconvenience of frequent manual recharging.

Síntese e caracterização de filmes de Polipirrol dopados com Tetraquis(4-carboxifenil) porfirina para aplicações fotoelectroquímicas

Photoelectrochemistry is emerging as a promising technology for harvesting and utilizing solar energy in a wide range of applications. However, electrode materials still need to be improved to achieve optimal performance. Conductive polymers emerge as particularly promising organic compounds for this purpose due to their highly versatile properties. In this study, the galvanostatic synthesis of polypyrrole films co-doped with tetrakis(4-carboxyphenyl) porphyrin (PPy/TCPP) on fluorine doped tin oxide (FTO)-coated glass substrates was performed for the first time. In addition, an evaluation of these films as photoelectrodes was performed, focusing on key properties. The incorporation of porphyrin into the polymer matrix was confirmed by UV-Vis and IR characterization. SEM micrographs showed the morphological changes induced by the codopant. Cyclovoltammetry was used to evaluate the conductivity of the film, its electroactivity, electroactive area and HOMO energy level. The chopped chronoamperometry confirmed the photoactivity of the material and its stability for 3000 s. The electrical and optical properties of the polymer were characterized by EIS and light absorption measurements to propose its energy level diagram. The PPy/TCPP coatings were obtained with high homogeneity on FTO, good conductivity, quasi-reversible electrochemical activity to ferrocene probe and stable photoactivity. Electrical characterization indicates high charge flow under illumination. An indirect bandgap of 2.51 eV and a HOMO level value of -4.59 eV were obtained for PPy/TCPP.

Performance potential of fully-passive airborne wind energy system based on flapping airfoil

In the field of renewable energy, high-altitude wind energy emerges as a promising source, particularly at altitudes (>300 m) where conventional wind turbines cannot reach. Currently, the Airborne Wind Energy System (AWES) stands as the major technology for high-altitude wind energy harvesting, but confronts challenges including increasing performance enhancement, system robustness, and cost reduction. In response to these challenges, we developed a fully-passive AWES that employs a self-excited flapping airfoil to efficiently transfer wind energy to the ground. We study and optimize this fully-passive AWES with fluid-structure interaction method in a numerical wind tunnel, achieving a notable power coefficient of 1.17 and efficiency of 20 % with an average tether angle near 30°. We find that a thin airfoil with a slight camber near the leading edge outperforms other profiles. Increasing the pitching axis distance, the imbalance distance, the spring stiffness, and the pitching moment of inertia can improve the energy harvesting performance, but decreased the system robustness. We offer essential guidelines for setting initial parameters of the AWES, facilitating the design and deployment of this innovative technology. This work underscore that the fully-passive AWES is capable of realizing high-altitude wind energy harvesting with simplified structure and outstanding energy-harvesting performance.