Sustainable Harvesting Research Articles

Internet of Things Based Smart Shoe Fitness Tracker Prototype

In the modern era wearable smart technologies are highly popular and liked by the people of this generation. Smart shoe being one of the smart technologies, hypermarkets like Nike, Puma, Adidas, Xiaomi, keep launching various types of smart shoes for different purposes. Fitness being a mandatory factor in an individual’s lifestyle, people’s attention is drawn towards smart technologies meant to improve their fitness and monitor their workout routine on an everyday basis. However, there are few noticeable limitations that hinders people to not own a pair for themselves. In this paper, Internet of Things based smart shoe fitness tracker prototype has been developed considering the factors of cost, efficiency and sustainable energy. The prototype mimics the purpose of smart shoe fitness tracker where the fitness variable and health parameters are measured according to the user’s motion. The smart shoe mobile application facilitates as the user interface to monitor their day-to-day vitals and activity at real time using Internet of things. Integrating the concept of sustainable energy and energy harvesting from alternative energy resources using piezoelectric sensors to activate the tracker during fitness performance. As a result, this study has developed a smart shoe prototype that compensates the limitations of the existing smart shoes and motivates people to take up fitness as a part of everyday lifestyle and progressing towards a better future.

Analysis of Medicinal Plants and Traditional Knowledge Development in Ethiopia

As the review conducted Ethiopia has richened by medicinal plant species and traditional knowledge that have a significant role in the management of various human and livestock diseases. Medicinal plants are vastly used by the communities particularly rural communities to treat various human and livestock aliments.Medicinal plants also important for the development of modern medicine. Traditional knowledge is the accumulation of communities’ knowledge according to their cultures, beliefs, and experiences. Different parts of medicinal plants are used for traditional remedies in order to cure human beings and livestock. Traditional knowledge and medicinal plants are critically threatened and extinct due to overgrazing, charcoal production, deforestation, urbanization, agricultural expansion, and fire wood collection. Traditional medicinal plants and associated knowledge can be conserved using either in-situ or ex-situ conservation methods. Therefore, create awareness among the local people about the use of medicinal plants and the associated knowledge to ensure sustainable harvesting of medicinal plants. Conducting ethnobotanical research and documented medicinal plants and indigenous knowledges is very important for conserve.

Productivity and Costs of Mechanized Skidding operations at Sao Hill Forest Plantation, Tanzania

Due to global advancement of technology in forest operations, utilization of advanced machineries such as grapple skidder (GS) in timber harvesting has been increasing in the last decades. However, in order to understand their contribution in sustainable harvesting operations, it is important to understand their performance under different operating environment. Therefore, this study aimed to quantify productivity and cost of mechanised skidding operations at Sao Hill Forest plantation (SHFP). Six variables; diameter at a breast height (dbh), tree height, skidding distance, slope, costs, and cycle time (determined using detailed continuous time study) were collected in 120 GS observations.GS productivity and costs were estimated using productive machine hour (PMH) and delays inclusion approach. Regression models were developed using a generalized linear model (GLM) approach. GS productivity under PMH was 2.6% higher than the one including delay time, while skidding costs was 2.1% higher in the approach including delays. This study revealed significant variations (p-value <0.05) in productivity and cost on various terrain classes. At 0 m – 50 m distance, an average delays free GS productivity was 85.5 m3/h, with costs amounting to 1.7 USD/m3. On the distance exceeding 150 m, productivity dropped to 20.1 m3/h, and costs increased to 12.7 USD/m3. Likewise, in 0.0% - 10.0% slope range, average delays free GS productivity and costs was 100 m3/h and 1.5 USD/m3 respectively, while at 20.1% - 30.0% slope range, productivity dropped to 32.6 m3/h and costs raised to 3.9 USD/m3. Skidding distance, slope, and volume per trip were robust predictors of the GS productivity and costs, yielding pseudo-R2 values of 58.1% and 64.3%, respectively. Therefore, this study developed statistical models useful for predicting GS productivity and costs, however, their applications are recommended to be within the ranges of the variables used to develop the models.

(Invited) Two-Dimensional Low-Toxicity Absorbers for Efficient and Air-Stable Indoor Photovoltaics

The toxicity and bioavailability of lead (Pb) in halide perovskites motivates the search of Pb-free perovskite-inspired materials (PIMs), which would replicate the great optoelectronic properties of the traditional Pb-based counterparts. Among them, pnictohalides employing antimony or bismuth are especially attractive due to their low toxicity and inherent air stability. Their wide bandgaps (⁓2 eV) can broaden the application scenario beyond single-junction solar cells, being specifically suitable for e.g., silicon-perovskite tandems, indoor photovoltaics (IPVs), and photocatalysis.Despite outstanding indoor power conversion efficiencies up to 60% have been theoretically predicted for PIM-based IPVs, this research is still in a very early stage. In this talk, I will highlight some of our key findings on two-dimensional Sb- and/or Bi- based two-dimensional pnictohalides for sustainable indoor light harvesting. The considerable presence of both intrinsic and surface defects in wide-bandgap PIMs is mostly responsible for the modest indoor power conversion efficiency (PCE(i)) reported so far up to ⁓5% at 1000 lux white LED illumination. I will discuss the effective defect mitigation strategies relying on compositional engineering that we proposed to significantly improve the PCE(i) up to nearly 10% (9.53%). Our extensive characterizations at both material and device level evidence the successful suppression of trap-assisted and interfacial charge recombination as the result of a reduced defect density within the PIM domains and/or at their surface.The importance of our findings for the energy research community (within and beyond halide perovskite) lies in promoting future compositional design effort to reduce the defects in the next-generation wide-bandgap absorbers for eco-friendly energy generation and consumption.

High performance analysis and optimization of metal halide perovskite-based thermoelectric generators for sustainable energy harvesting

Metal halide perovskite-based thermoelectric materials have garnered considerable attention due to their ultralow thermal conductivities and decent electric transport properties, while the research into thermoelectric generators (TEGs) lag much behind the progress of materials. In this paper, a real-sized 3D finite element model of a metal halide perovskite-based TEG is established under iso-thermal and iso-heat flux boundary conditions. Compared with traditional PbTe-based TEGs, perovskite-based TEGs exhibit more promising TE performance with TE conversion efficiency reaching ∼12 % at a 104 W/m2 thermal input power. In addition, the geometric parameters as well as the thermal management parameters under the iso-heat flux boundary condition, are optimized and discussed. The Taguchi optimization combined with the analysis of variance (ANOVA) method is further employed to quantify the contribution and importance of these factors on the output performance of the perovskite-based TEG. The results demonstrate that changing the device geometry and thermal management parameters will affect the temperature distribution between the hot- and cold-side. The thermal input power and the height of the p-n legs are the dominant factors affecting the output power and the TE conversion efficiency of the perovskite-based TEG. Promisingly, the TE conversion efficiency can reach above 20 % (or 65 % of the corresponding ideal Carnot efficiency) for an optimized perovskite-based TEG. This work predicts and verifies the highly promising TE performance of new metal halide perovskite-based TEGs. The principles behind the analyses here provide new strategies for designing and optimizing TEGs for waste-heat harvesting and other sustainable energy conversion applications.

Triboelectric nanogenerator based on reactivated electrode materials derived from waste alkaline battery: Influence of pyrolysis temperature and surface morphology

Triboelectric nanogenerators (TENGs) have been extensively studied in recent years due to their potential for energy harvesting and self-powered sensing. However, most of the research has focused on only exploring new materials, while there has been limited examination of how optimizing material properties or device system designs could enhance the TENG devices' performance. To address this gap, this research presents a pioneering approach using thermally reactivated electrode materials derived from waste alkaline batteries (WABs) for future energy harvesting applications in TENGs. By systematically investigating how the oxygen content and surface morphology affect TENG device performance at different pyrolysis temperatures, we achieved optimal TENG material at 500 °C, exhibiting outstanding output voltage, current, and power density of 790 V, 40.27 µA, and 529.375 µW/cm2, respectively. Mechanical stability testing revealed that the TENG device based on RC-WABs remains stable for over 40,000 cycles with consistent output performance. Furthermore, the proposed method employs a simple and efficient pyrolysis technique to reactivate the cathode and anode materials of WABs, operating at low temperatures without activating gases or inert atmospheres. To validate real-time applicability, the TENG device was successfully employed to power various applications, such as illuminating 150 LEDs and operating a digital calculator. This research provides a new perspective on the use of waste materials for energy harvesting applications and offers a potential solution for recycling waste alkaline batteries, which is one of the significant environmental problems. Overall, the findings highlight the potential of the proposed approach for future TENG device design and provide a new direction for sustainable energy harvesting.

Understanding fishing and conservation of the Pacific seahorse (Hippocampus ingens) in Sinaloa, Mexico, through local ecological knowledge

Abstract The Pacific seahorse (Hippocampus ingens) is a teleost fish native to the Pacific Ocean. In Mexico they are protected by national legislation; however, there are no studies regarding their commercial use or population status. From a conservation perspective they are a threatened fish and from a socio‐economic aspect they represent a source of income for many fishing communities. The integration of these two points of view requires, among other things, the recognition that fishers have knowledge and skills that can help implement conservation strategies and management plans for seahorses and their habitats. The objective was to document the knowledge of fishers from Sinaloa about the fishing status and current commercialization of wild populations of H. ingens. For this, semi‐structured interviews and participatory observation were carried out with 112 participants in the two main ports of the state of Sinaloa (Mazatlán and Topolobampo) from July to August 2021. The data obtained were coded and then, through content analysis, systematized results were obtained that allowed a qualitative and quantitative analysis. The species was found to be caught using six different fishing gears (catch per unit effort, CPUE = 0.07–1.24 seahorses per boat per day) and have an important financial value. Most fishers catch seahorses incidentally, but three of them mentioned targeting them directly. Fishers perceive a decrease in catches and in the size of the Pacific seahorse, as well as an increase in prices. The information analysed indicates that seahorse populations in Sinaloa are exploited and have economic value, despite current regulations. This study shows that the exploitation of seahorses in Sinaloa is unsustainable and requires the implemention of collaborative management strategies (e.g. stakeholder management, the establishment of marine protected areas, sustainable harvest practices, community‐based enforcement efforts, educational campaigns, research, and conservation partnerships) that fully take into account the knowledge and practice of local fishers of Sinaloa and Mexico.

Nature‐Driven Edible Black Soldier Fly (BSF) Insect Larvae Derived Chitin Biofilm for Sustainable Multifunctional Energy Harvesting

AbstractWith the increasing demand for portable electronic devices and the shortage of conventional energy resources, energy harvesting from natural resources has gained much attention. Herein, they proposed a black soldier fly (BSF) derived chitin biofilm to fabricate high‐performance triboelectric and piezoelectric nanogenerators. The physiochemical characterizations of the chitin biofilm are demonstrated by the presence of the hydroxyl group, alpha chitin, and beta chitin, which are responsible for the remarkable tribopositive, and piezoelectric function of the chitin derived from BSF. The electrical performance of the proposed work, such as voltage, current, and instantaneous power from BSF/PTFE‐based triboelectric nanogenerator (TENG) are exhibited at 121 V, 15 µA, and 217.8 µW, respectively. Ag/BSF/Ag piezoelectric nanogenerator (PENG) is generated 18 V voltage, 2.2 µA current, and 5 µW instantaneous power. Moreover, the proposed TENG and PENG devices demonstrate the ability to charge the dielectric capacitors and drive low‐power electronic devices like LEDs and a calculator. The proposed results suggested that chitin is a superior biomaterial for developing sustainable energy harvesting devices.

Stark differences in spatial gradients of Eastern oyster (Crassostrea virginica) productivity in two Florida, USA, estuaries

The eastern oyster (Crassostrea virginica) is a foundation species in U.S. Atlantic and Gulf coast estuaries because of its numerous ecosystem services and importance to local fisheries. Concerns about the persistence and sustainable harvesting of oysters in the state of Florida is growing due to environmental factors (e.g., increased predation, salinity, and disease) and increased harvesting pressure. Thus, we need to understand which estuary locations are best suited for conservation or restoration efforts. Here, we use a combination of field experiments and modeling to assess the potential oyster productivity at sites throughout two estuaries at the same latitude but in different ocean basins: Apalachicola Bay (Gulf of Mexico coast) and the Guana Tolomato Matanzas National Estuarine Research Reserve (GTM, Atlantic coast). Our population model used the per-recruit approach from fisheries science, allowing us to combine field data on growth and mortality to estimate productivity (measured as lifetime spawning output) in an elegant way, without requiring assumptions about unknown larval supply processes. Subtidal Apalachicola Bay oysters exhibit an expected pattern, with greater productivity in the inner estuary nearer the river mouth and predation reducing productivity in the seaward direction. In contrast, intertidal GTM oysters do not exhibit strong spatial gradients, with little effect of predators and slightly higher productivity near the river mouth; intertidal oysters in Apalachicola exhibited similar productivity and lack of predator effect. We attribute these differences in oyster productivity to differences in tidal exposure, the predator community, and hydrology of oyster reefs at the two study sites. Thus, we would give diverging recommendations for spatial prioritization of restoration and conservation efforts. Additionally, these results lead us to caution against generalized statements about spatial patterns of oyster productivity within estuaries without consideration of the predation context.

Application of Conventional and Improved Techniques in Felling and Skidding to Residual Stand Damages

Felling and skidding are essential in the timber extraction process. But on the other hand, residual stand damage can’t be avoided. This study aimed to analyze the impact of conventional and improved felling and skidding techniques on residual stands in natural forests. Three observation plots were developed to identify the types, numbers, and criteria of residual stand damage due to both techniques. The criteria were categorized as a) minor damage (&lt;25%), b) moderate damage (25–50%), and c) major damage (&gt;50%). It showed that the conventional felling and skidding technique caused damages of 14.92% dominated by tree crown damage and 16.70% dominated by stem wounds, respectively. The residual stand damage due to conventional felling and skidding technique was 31.62% categorized as medium damage. Meanwhile, improved felling and skidding techniques caused damage of 9.89% dominated by broken trees, and 10.27% dominated by stem wounds, respectively. The residual stand damage due to improved felling and skidding technique was 20.16% categorized as minor damage. The improvement techniques can minimize residual stand damage by 36.24%. Therefore, a good understanding of forest concessionaires regarding RIL principles is necessary for achieving sustainable timber harvesting

Addressing complex fleet structure in fishery stock assessment models: Accounting for a rapidly developing pot fishery for Alaska sablefish (Anoplopoma fimbria)

Fisheries management operates under uncertainty, often driven by the dynamic nature of marine ecosystems and associated fisheries. Stock assessment models, which form the scientific basis of decision-making in fisheries management, strive for realistic representations of biological and fishery processes. However, data limitations and knowledge gaps necessitate simplifying assumptions for representing these complex bio-socioeconomic systems, which can increase uncertainty in the assessment process. Addressing time-varying fishery dynamics (i.e., due to regulatory changes or alterations in harvester behavior) is a common and particularly challenging problem for stock assessment models. Time-varying fishery selectivity is widely utilized to address changes in fishery dynamics but may not be adequate when regulatory changes substantially alter gear usage and associated assessment fleet structures. We explore the implications of accounting for, or ignoring, complex temporal changes in fleet structure and selectivity within stock assessment models by utilizing a recent and high-value case study, Alaska sablefish (Anoplopoma fimbria). Our findings demonstrate that the treatment of fleet structure (i.e., adding fleet complexity to account for gear transitions) did not greatly influence estimates of spawning biomass trajectories. However, associated selectivity assumptions had substantial impacts on sustainable harvest recommendations. We recommend that the treatment of fleet structure and associated selectivity assumptions should incorporate a priori considerations and subject-matter expertise of fishery and biological dynamics to ensure pragmatic and appropriate model parameterizations. Moreover, we advocate for multi-fleet models as a useful diagnostic tool for validating model estimates from single-fleet assessments when uncertainty in fleet dynamics exist.

Nanosheet Zinc Oxide Synthesized by Solution-Immersion Method for Triboelectric Nanogenerator

Most global problems are being solved by using sustainable energy harvesting technologies to retain the social ecosystem in great condition. The triboelectric nanogenerator (TENG) which is a renewable energy harvesting device, collects the waste mechanical energy from its surroundings and performs the electric signal conversion. TENG have garnered increased attention in recent years by offering prospective use in energy harvesting technology. Particularly, there is a need for flexible energy conversion that serves as a power supply for portable electronic equipment. In this study, ZnO nanosheet thin film prepared on the flexible conductive aluminium foil through a low temperature immersion technique was used to generate electrical energy. The effect of heat treatment on ZnO nanosheet thin film was also investigated on the surface morphology, strutural properties and nanogerator performance. The high density of interconnected ZnO nanosheet were observed before and after heat treatment as confirmed by FESEM studies. The analysis using XRD confirmed that ZnO nanosheet thin film was successfully deposited on the aluminium foil. Additionally, the ZnO nanosheet thin films improved significantly with heat treatment, enhancing their crystalline quality. The triboelectric nanogenerator (TENG) was successfully constructed in contact and separation mode using Kapton tape on top and ZnO nanosheet thin film on the bottom to generate electricity by a force of hand pressing. The output electrical voltage of the device doubled from around 2 V to 4 V after underwent the heat treatment. This study provides an essential insight into fabrication of TENG using the ZnO nanosheet thin film through a clean and effective method for nanogenerator applications.

Electro-Responsive Breathing Transition of Conductive Hydrogel for Broadband Kinetic Energy Harvesting.

Reclaiming kinetic energy from vibrating machines holds great promise for sustainable energy harvesting technologies. Nevertheless, the impulsive current induced by vibrations is incompatible with conventional energy storage devices. The energy-management system necessitates novel designs of soft materials for lightweight, miniaturized, and integrated high-frequency electrochemical devices. Here, this work develops a conductive hydrogel with an electro-responsive polymeric network. The electro-responsive breathing transition of the crosslinking points facilitates the expeditious formation of a localized electrolyte layer. This layer features an exceedingly high local charge density, surpassing that of a saturated electrolyte solution by an order of magnitude, and thus enabling rapid charge transport under the influence of an applied voltage. The micro-capacitor based on the gel exhibits record-high capacitance of ≈2 mF cm-2 when the frequency of energy input reaches up to 104 Hz. This work also demonstrates a prototype battery charger that harvests energy from a running car engine. This study presents a feasible strategy for waste energy recycling using integrated electrochemical devices, opening a new avenue for ambient energy management.

Sustainable harvest: exploring sugar palm trees as a green economy catalyst in Bukit Kaba Natural Park, Bengkulu, Indonesia

Conservation areas are synonymous with protected areas and is prohibited for social and industrial activities that damage the environment. How ever, this research found in which at Bukit Kaba, the use of conservation areas could support the preservation of the natural environment. This article explained that by finding niche commodities, conservation areas can generate many economic benefits for the surrounding community and preserve the natural environment at the same time. This research was environmental qualitative research conducted at conservation area of the Bukit Kaba, Bengkulu, Indonesia. Data were obtained through observation, interviews, document studies, and focus group discussion with the Bukit Kaba conservation area stakeholders. The research team stayed for 20 days in Rejang Lebong district and visited community groups while conducting observations and interviews. The research concluded that the agreement between farmer groups and the Balai Konservasi Sumber Daya Alam (Nature Conservation Agency) to maintain and cultivate sugar palm trees at Bukit Kaba conservation area is an excellent green economic practice. The agreement stipulated the palm trees growing in the Bukit Kaba conservation area as a niche commodity because it can provide multiple benefits. On the one hand, palm trees provide economic benefits to residents around the conservation area. On the other hand, palm trees help maintain land and soil resilience in the Bukit Kaba area.

Gd3+–Ho3+-Dy3+]:CsPbI2.2Br0.8: Lanthanide impelled stabilization of perovskite material for sustainable energy harvesting, generation, and charge storage

This work presents the first systematic investigation of the novel [Gd3+–Ho3+-Dy3+]:CsPbI2.2Br0.8 (GHD:CPVSK) hetero-structure and explores it for energy applications. The optical constancy of GHD:CPVSK was explored for 28 days and it spanned around 1.63 – 1.68 eV, expressing remarkable stability in band energy. This material was identified with the cubic phase and possessed typical ABX3 type of crystalline geometry. GHD:CPVSK was used as an absorber layer inside regular perovskite solar cell. It improved the overall photovoltaic operation with the 16.56 % efficiency and 75.89 % fill factor reflecting the excellent perovskite film quality. As an electro-catalyst, the pure hydrogen production activity of GHD:CPVSK excelled over oxygen generation with the lower overpotential and Tafel slope value of 142 mV and 117.3 mV dec−1. Also, this electro-catalyst was electrochemically intact in electrolyte environment for 100 min. In terms of the charge storing capacity for battery, GHD:CPVSK embellished electrode has 470.66 mAh g−1 of unit capacity and impressively minimal equivalent series resistance (Rs) of 0.41 Ω. The developed material stabilized by lanthanide doping has expressed excellency for diverse energy associated applications and systems in a cost effective, facile, and sustainable manner.

Factors promoting hunting groups’ sustainable harvest of moose in a co-management system

Collaboration between and within management levels and involvement of local communities (co-management) increases sustainable management of natural resources. In Finland, moose (Alces alces) are harvested by hunting groups within a co-management system, providing meat and social benefits. We computed the 14-year change in moose harvest (2007–2020) for 4320 hunting groups. Moose harvest declined on average 1.1% per year, but with substantial variation in moose harvest changes between the hunting groups. We extracted information describing the collaboration between the hunting groups, their democratic status as well as leader dynamics, and the year of establishment. A hunting group’s moose harvest was more stable (i.e. declined less) when the hunting group was (1) established a longer time ago; (2), had more changes in leadership over time, but did not depend on collaboration with other local hunting groups (in terms of jointly holding moose hunting licenses), whether the hunting group was a registered society (presumed to be more democratic than a non-registered one) or had consecutive leaders that shared a surname (presumed to be related). We conclude that encouraging resource users’ early establishment in groups and groups’ long-term persistence and promoting democratic leadership roles improves stable benefits from a natural resource in a co-management system.

Fabrication of PVDF/PMMA Polymer for Sustainable Energy Harvesting

Abstract: The synthesis of blends that combine properties of two or more polymeric materials is increasingly investigated due to the versatility of the synthesis and its growing potential for many applications, including sustainability. Their characteristics are defined mainly by the synthesis conditions. Therefore, this paper details the synthesis process of easy-to-handle films using mixing method. The procedures and drawbacks found during the preparation of composite films are described. Polymeric compounds formed by the mixture of polyvinylidene fluoride (PVDF) and polymethyl methacrylate (PMMA) are addressed, varying the concentration, and evaluating their impact on the piezoelectric capacity. Films were formed through the spin-coating technique and characterized by optical and holographic microscopes. The results showed that composites with a concentration of 50 wt.% or larger of PVDF in the blend acquire a morphology with a granular appearance, however at lower concentrations they present a homogeneous morphology similar to that of PMMA. A homogeneous distribution of PVDF in the PMMA stands out. However, excessive contents of PMMA are associated to peaks and non-uniformities detected like multicolored regions by digital holography. Controlled strength-strain laboratory tests allowed to evaluate the film blends performance. The results indicate noticeable improvements in voltage output for a composition 70wt% PVDF and 30 wt% PMMA.

Wood volume is overestimated in the Brazilian Amazon: Why not use generic volume prediction methods in tropical forest management?

The Amazon has a range of species with high potential for sustainable timber harvesting, but for them to be utilized globally, the merchantable wood volume must be accurately quantified. However, since the 1950s, inadequate methods for estimating merchantable timber volumes have been employed in the Amazon, and Brazilian Government agencies still require some of them. The natural variability of the Amazon Forest provides an abundance of species of different sizes and shapes, conferring several peculiarities, which makes it necessary to use up-to-date and precise methods for timber quantification in Amazon Forest management. Given the employment of insufficient estimation methods for wood volume, this study scrutinizes the disparities between the actual harvested merchantable wood volume and the volume estimated by the forest inventory during the harvesting phase across five distinct public forest areas operating under sustainable forest management concessions. We used mixed-effect models to evaluate the relationships between inventory and harvested volume for genera and forest regions. We performed an equivalence test to assess the similarity between the volumes obtained during the pre-and post-harvest phases. We calculated root mean square error and percentage bias for merchantable volume as accuracy metrics. There was a strong tendency for the 100% forest inventory to overestimate merchantable wood volume, regardless of genus and managed area. There was a significant discrepancy between the volumes inventoried and harvested in different regions intended for sustainable forest management, in which only 22% of the groups evaluated were equivalent. The methods currently practiced by forest companies for determining pre-harvest merchantable volume are inaccurate enough to support sustainable forest management in the Amazon. They may even facilitate the region's illegal timber extraction and organized crime.

Applications of Sustainable Hybrid Energy Harvesting: A Review

This paper provides a short review of sustainable hybrid energy harvesting and its applications. The potential usage of self-powered wireless sensor (WSN) systems has recently drawn a lot of attention to sustainable energy harvesting. The objective of this research is to determine the potential of hybrid energy harvesters to help single energy harvesters overcome their energy deficiency problems. The major findings of the study demonstrate how hybrid energy harvesting, which integrates various energy conversion technologies, may increase power outputs, and improve space utilization efficiency. Hybrid energy harvesting involves collecting energy from multiple sources and converting it into electrical energy using various transduction mechanisms. By properly integrating different energy conversion technologies, hybridization can significantly increase power outputs and improve space utilization efficiency. Here, we present a review of recent progress in hybrid energy-harvesting systems for sustainable green energy harvesting and their applications in different fields. This paper starts with an introduction to hybrid energy harvesting, showing different hybrid energy harvester configurations, i.e., the integration of piezoelectric and electromagnetic energy harvesters; the integration of piezoelectric and triboelectric energy harvesters; the integration of piezoelectric, triboelectric, and electromagnetic energy harvesters; and others. The output performance of common hybrid systems that are reported in the literature is also outlined in this review. Afterwards, various potential applications of hybrid energy harvesting are discussed, showing the practical attainability of the technology. Finally, this paper concludes by making recommendations for future research to overcome the difficulties in developing hybrid energy harvesters. The recommendations revolve around improving energy conversion efficiency, developing advanced integration techniques, and investigating new hybrid configurations. Overall, this study offers insightful information on sustainable hybrid energy harvesting together with quantitative information, numerical findings, and useful research recommendations that progress and promote the use of this technology.

Energy harvesting using an inverted piezohydroelastic flag with resistor–inductor–capacitor circuit

We develop a high-fidelity multi-physics model and, by using it, study the energy conversion process of a piezohydroelastic flag. Instead of a regular flag with a clamped upstream leading edge, we use an inverted flag so as to make the best of fluid elastic instability for energy harvesting. Moreover, different from many previous studies where a resistor–capacitor (RC) circuit is usually used, we adopt a resistor–inductor–capacitor (RLC) circuit for electricity generation. The influences of several key parameters associated with fluid, structure and electric dynamics are studied. Significantly different response modes are identified, among which the symmetric- and asymmetric-flutter modes are most suitable for sustainable energy harvesting, both emerging with moderate bending stiffness. If only deploying the RC circuit, increasing the resistance makes the flag more stable. By adding an inductor to turn the RC circuit into an RLC one, we observe the occurrence of ‘lock-in’ between the flag frequency and the circuit frequency as first reported on a regular flag by Xia et al. (Phys. Rev. Appl., vol. 3, 2015, 014009). This phenomenon can significantly enhance the energy output, but it only happens when the circuit resistance is sufficiently large. From a derivation based on dynamic mode decomposition analysis, we further identify an optimal condition for maximizing the energy output, which can serve as a guideline to determine whether deploying an inductor can boost the performance, and, if yes, the required inductance. The findings from this study can better guide the design of flow-induced-vibration-based piezoelectric energy harvesters for microelectronic devices.