Mechanical Harvesting Research Articles

Comparison and Experimental Study of Cotton Stalk Extraction via Nip Roller Based on Nip Motion Trajectory Equation

In the field of straw recycling, a cotton straw-harvesting mechanism is an important piece of agricultural equipment. The mechanistic analysis method of the harvesting mechanism is a major focus of research and development in this field. Currently, in the mechanistic analysis of the cotton straw recycling mechanism, the kinematic and mechanical analysis of the recycling mechanism is generally the main focus. There is not a lot of research based on the quantitative analysis between different recycling mechanisms. In this study, a clamped cotton straw pulling mechanism is optimized and designed, and two different pulling structures are designed. In addition, a two-dimensional modeling and analysis method is used to establish the two-dimensional equations of motion of the two pulling mechanisms, analyze the leakage and breakage rates of the two clamping structures, predict the final pulling effect, and verify the results of the field tests. According to the analysis, the belt-clamping side has more uniform clamping stress and a larger clamping contact area than the chain-clamping side, and the tangential stress on cotton straw is smaller. Based on the field-test verification, the band-clamping side had a higher pulling net rate by an average of 19.32% and a lower missed pulling rate by an average of 6.01% than the chain-clamping side. Therefore, it was determined that the main reason for the lower pulling net rate of the chain-gripped side than that of the belt-gripped side was the higher pulling breakage rate, and the secondary reason was the high leakage pulling rate. Thus, the feasibility and accuracy of the analytical method of this study are verified.

Textile‐based triboelectric nanogenerators integrated with 2D materials

AbstractThe human body continuously generates ambient mechanical energy through diverse movements, such as walking and cycling, which can be harvested via various renewable energy harvesting mechanisms. Triboelectric Nanogenerator (TENG) stands out as one of the most promising emerging renewable energy harvesting technologies for wearable applications due to its ability to harness various forms of mechanical energies, including vibrations, pressure, and rotations, and convert them into electricity. However, their application is limited due to challenges in achieving performance, flexibility, low power consumption, and durability. Here, we present a robust and high‐performance self‐powered system integrated into cotton fabric by incorporating a textile‐based triboelectric nanogenerator (T‐TENG) based on 2D materials, addressing both energy harvesting and storage. The proposed system extracts significant ambient mechanical energy from human body movements and stores it in a textile supercapacitor (T‐Supercap). The integration of 2D materials (graphene and MoS2) in fabrication enhances the performance of T‐TENG significantly, as demonstrated by a record‐high open‐circuit voltage of 1068 V and a power density of 14.64 W/m2 under a force of 22 N. The developed T‐TENG in this study effectively powers 200+ LEDs and a miniature watch while also charging the T‐Supercap with 4‐5 N force for efficient miniature electronics operation. Integrated as a step counter within a sock, the T‐TENG serves as a self‐powered step counter sensor. This work establishes a promising platform for wearable electronic textiles, contributing significantly to the advancement of sustainable and autonomous self‐powered wearable technologies.image

Fast Transfer of Triplet to Doublet Excitons from Organometallic Host to Organic Radical Semiconductors.

Spin triplet exciton formation sets limits on technologies using organic semiconductors that are confined to singlet-triplet photophysics. In contrast, excitations in the spin doublet manifold in organic radical semiconductors can show efficient luminescence. Here the dynamics of the spin allowed process of intermolecular energy transfer from triplet to doublet excitons are explored. A carbene-metal-amide (CMA-CF3) is employed as a model triplet donor host, since following photoexcitation it undergoes extremely fast intersystem crossing to generate a population of triplet excitons within 4ps. This enables a foundational study for tracking energy transfer from triplets to a model radical semiconductor, TTM-3PCz. Over 74% of all radical luminescence originates from the triplet channel in this system under photoexcitation. It is found that intermolecular triplet-to-doublet energy transfer can occur directly and rapidly, with 12% of triplet excitons transferring already on sub-ns timescales. This enhanced triplet harvesting mechanism is utilized in efficient near-infrared organic light-emitting diodes, which can be extended to other opto-electronic and -spintronic technologies by radical-based spin control in molecular semiconductors.

Enhancement of the piezoelectric performance of GN nanosheets/PVDF nanocomposite film using electrostatic layer and penetrated electrode

The efficiency of the piezoelectric nanogenerator is a vital factor for the superior performance of the nanogenerator to achieve a green and eco-friendly technology in the development of modern electronics. Piezoelectric nanogenerators (PNGs) have limited use in mechanical energy harvesting due to their low output performance. The output has been a major source of concern for PNG's development. A new design of PNG based on g-C3N4 nanosheets(GN)/PVDF nanocomposite film (GPNC) using penetrated Cu electrode and electrostatic layer is proposed to overcome this problem. By creating numerous peripheral contacts within the piezoelectric material, the overall number of surface polarization charges increased. Also, an electrostatic contribution from graphene oxide contributes to an increased output voltage. The syngeristic effect of high % γ-nuclei, penetrated electrode, and electrostatic effect is supposed to vital for carry out significant piezoelectric outputs (V∼34.4 V and I ∼3.2 µA) and superior force sensitivity (0.93 V/kPa). In practical applications, the designed PNG can competently harvest electrical energy from various human movements, and also can detect low physiological actions. Our work offers a simple but effective perspective for high-performance piezoelectric nanogenerator fabrication and progress a stride toward self-powered day-to-day used electronics.

Assessing mechanical and stray magnetic field energy harvesting capabilities in lead-free PVDF/BCT-BZT composites integrated with metglas

The exploration of energy harvesting encompasses a wide array of sources, with a specific focus on recovering mechanical and magnetic energy from overlooked outlets, driving current research endeavours. In this study, we developed highly flexible Magneto-Mechano-Electric (MME) harvesters by combining poly(vinylidene fluoride) (PVDF)/barium calcium zirconium titanate (BCT-BZT) composite films with metglas. The flexible piezoelectric polymer-ceramic composite films were fabricated using a solvent casting technique. The high piezoelectric BCT-BZT fillers were synthesized through a sol-gel reaction route. A thorough analysis was carried out on these composites to evaluate their structural, functional, microstructural, and dielectric properties. The composite film loaded with 20 wt% BCT-BZT filler achieved a 78 % β-phase with a significant enhancement in the dielectric properties, resulting in a high permittivity∼40 and low dielectric loss. Employing these films, we engineered nanogenerators capable of converting mechanical energy into electrical energy, yielding an output voltage of 11 V. Thereafter, to harvest mechanical and stray magnetic fields, we developed a MME generator comprising a magnetic Metglas layer and PVDF-BCT-BZT composite and achieved an output voltage of 3.3 V with a power density of 85 μW/m2 when subjected to an AC magnetic field of 5 Oe. Furthermore, the MME generator has demonstrated the ability to charge various capacitors showcasing its potential for usage in self-powered, non-contact, and implantable devices.

Flexible, bilayered piezoelectric composite based on large-scale inorganic PZT film and organic P(VDF-TrFE) membrane for mechanical energy harvesting

Piezoelectric composites based on organic fluoropolymers and inorganic ceramic are attractive for mechanical energy harvesters due to their intriguing attributes of mechanical flexibility and piezoelectricity. However, the poor dispersion and random distribution of ceramic fillers in the polymer matrix not only decrease the toughness but also produce poor electrical performance. Here, a novel flexible piezocomposite with a bilayered structure based on large-sized inorganic PbZr0.52Ti0.48O3 (PZT) thin film and organic P(VDF-TrFE) membrane is developed via a simple layer-by-layer method. To realize flexibility, PZT film are fabricated on unique two-dimensional mica substrate. Then P(VDF-TrFE) membrane with polar β-phase is in situ coating on the surface of the PZT film. The resulting composite can effectively convert external strain into electrical signals with output voltage of 4 V and current of 180 nA in a bending-releasing mode of 60°. Experiment and finite element simulations illustrate that the output performance in the bilayered composite is optimized due to the synergistic effect of PZT and P(VDF-TrFE) functional layers. Besides, the composite based energy harvesters can be employed in versatile dynamics monitoring from daily physiological motions to human-machine interface. This study proposes a feasible approach to design high-performance flexible piezoelectric composite, possibly contributing to the blossoming of wearable/portable electronics.

Activation of TADF in Photon Upconverting Crystals of Dinuclear Cu(I)-Iodide Complexes by Ligand Engineering.

This work reports that ligand engineering can modulate the triplet harvesting mechanism in iodide-bridged rhombic Cu2I2 complexes. Complex-1, with a smaller Cu-Cu distance, exhibits phosphorescence from 3(M+X)LCT and 3CC states with 66% quantum yield, whereas an increased Cu-Cu distance in complex-2 results in a switch of the emission from phosphorescence to TADF, which occurs via 1/3(M+X)LCT states with 83% quantum yield. The TADF property of complex-2 has been utilized for the fabrication of a pc-LED emitting efficient warm white light. Moreover, the high charge-transfer nature of these complexes leads to the emergence of third-harmonic generation (THG). Interestingly, complex-1 exhibits efficient third-harmonic generation with a χ(3) value of 1.15 × 10-18 m2 V-2 and LIDT value of 14.73 GW/cm2. This work aims to provide a structure-property relationship to achieve effective harvestation of triplet excitons in iodide-bridged rhombic Cu2I2 complexes and their effective utilization in OLED device fabrication and nonlinear photon upconversion processes.

Comparison between Manual Harvesting and Mechanical Harvesting

Comparison between Manual Harvesting and Mechanical Harvesting

Submillimeter‐Scale Superlubric Triboelectric Nanogenerator

AbstractTriboelectric nanogenerator (TENG) for mechanical energy harvesting has been regarded as one of the most prospective energy technologies for the new era. However, inevitable material wear during triboelectrification results in output reduction and even failure of the TENG. In this work, a submillimeter‐scale superlubric TENG (SS‐TENG) is reported that enables ultra‐low friction coefficient (µ) and stable power generation. By using the micro/nano‐processing technology, the interdigital electrodes are embedded into the dielectric layer as a flat surface, on which the highly‐hydrogenated diamond‐like carbon (PLC) is deposited as the triboelectric layer to effectively reduce the friction coefficient. The frictional properties are systematically investigated at different parameters, in which a submillimeter‐scale (130 µm) superlubricity state (µ = 0.0084) is achieved at 4 N, 2 Hz and nitrogen atmosphere. Meanwhile, the SS‐TENG has a maximum power density of 3 mW m−2, which can remain stable at the superlubric condition. This work has first realized the freestanding‐mode superlubric TENG in submillimeter scale and provided a viable strategy for the development of long‐lifetime TENG, which may have great applications in frictional energy recovery from mechanical components, human joint motion, and the natural environment.

Phosphor‐Loaded Triboelectric Film‐Based Multipurpose Triboelectric Nanogenerators for Highly‐Efficient Energy Harvesting, Sensing, and Self‐Illumination Applications

AbstractA novel approach is proposed for combining phosphor materials with triboelectric nanogenerators (TENGs) for mechanical energy harvesting and illumination applications. For this purpose, strongly reddish‐orange‐emitting Ba0.5Sr0.5Nb2O6:0.25 mol Eu3+ (BSNb:0.25Eu) phosphor materials are synthesized. The photoluminescence properties of the synthesized BSNb:0.25Eu are analyzed. The synthesized BSNb:0.25Eu is utilized as a dielectric filler inside a polydimethylsiloxane polymeric film due to its high dielectric properties to improve the overall dielectric properties of the composite film (CF). TENG devices are fabricated using phosphor‐loaded CFs as the tribonegative layer, transparent polyvinyl alcohol as the tribopositive layer, and aluminum as the conductive electrode. All the TENGs operate in a contact‐separation mode, and the highest electrical output is attained by optimizing the phosphor filler concentration in the CF. The optimized TENG exhibits excellent stability in long‐term operational tests, under varying harsh ambient temperatures. Indium tin oxide sputtered on both triboelectric films as an electrode and combined with a transparent hard substrate to obtain a fully transparent TENG. A self‐illuminating TENG (SI‐TENG) is fabricated by integrating near‐ultraviolet light‐emitting diodes between two identical TENGs. The SI‐TENG can harvest the mechanical energy available in the surrounding environment and illuminate it as a light source. Additionally, the proposed phosphor‐loaded polymer films can be employed for optical thermometry and mechanical energy harvesting via SI‐TENG on a large scale.

High-performance flexible magnetic textile fabricated using porous Juncus effusus fiber for biomechanical energy harvesting

Mechanical energy produced by human motion is ubiquitous, continuous, and usually not utilized, making it an attractive target for sustainable electricity-harvesting applications. In this study, flexible magnetic Juncus effusus (M-JE) fibers were prepared from plant-extracted three-dimensional porous Juncus effusus (JE) fibers decorated with polyurethane and magnetic particles. The M-JE fibers were woven into fabrics and used for mechanical energy harvesting through electromagnetic induction. The M-JE fabric and induction coil, attached to the human wrist and waist, yielded continuous and stable voltage (2 V) and current (3 mA) during swinging. The proposed M-JE fabric energy harvester exhibited good energy harvesting potential and was capable of quickly charging commercial capacitors to power small electronic devices. The proposed M-JE fabric exhibited good mechanical energy harvesting performance, paving the way for the use of natural plant fibers in energy-harvesting fabrics.

A Four-in-One Compact Design of Monostable Quasi-Static-Toggling Mechanical Energy Harvester

A Four-in-One Compact Design of Monostable Quasi-Static-Toggling Mechanical Energy Harvester

A triboelectric nanogenerator based on TPU/PVDF electrospinning for mechanical energy harvesting and monitoring running step rate

A triboelectric nanogenerator based on TPU/PVDF electrospinning for mechanical energy harvesting and monitoring running step rate

Multi-omics analysis reveals the pivotal role of phytohormone homeostasis in regulating maize grain water content

Grain water content (GWC) is a key determinant for mechanical harvesting of maize (Zea mays). In our previous research, we identified a quantitative trait locus, qGWC1, associated with GWC in maize. Here, we examined near-isogenic lines (NILs) NILL and NILH that differed at the qGWC1 locus. Lower GWC in NILL was primarily attributed to reduced grain water weight (GWW) and smaller fresh grain size, rather than the accumulation of dry matter. The difference in GWC between the NILs became more pronounced approximately 35 d after pollination (DAP), arising from a faster dehydration rate in NILL. Through an integrated analysis of the transcriptome, proteome, and metabolome, coupled with an examination of hormones and their derivatives, we detected a marked decrease in JA, along with an increase in cytokinin, storage forms of IAA (IAA-Glu, IAA-ASP), and IAA precursor IPA in immature NILL kernels. During kernel development, genes associated with sucrose synthases, starch biosynthesis, and zein production in NILL, exhibited an initial up-regulation followed by a gradual down-regulation, compared to those in NILH. This discovery highlights the crucial role of phytohormone homeostasis and genes related to kernel development in balancing GWC and dry matter accumulation in maize kernels.

Construction and analysis of a mechanical model for viscoelasticity and plasticity in potato

AbstractThe aim of this paper is to develop a precise collision model of potatoes falling onto a separation sieve to assess their damage characteristics. A viscoelastic‐plastic mechanics model is created by integrating the collision process with the potato soil separation device. Test factors include fall height, potato mass, fall direction, and varieties. Potato deformation and damage volume serve as evaluation indices in single‐factor tests to explore their relationships with these factors. The model analyzes the collision loading and unloading process, studying relationships between parameters and test factors, examining the potato collision damage mechanism. Predictive equations for potato damage volume based on fall height, potato mass, and plasticity ratio λp are derived: V1 = 1606λp–537, V2 = 4751λp–2087, and V3 = 12617λp–5303. This study provides a theoretical foundation for analyzing potato collision damage and offers technical references for optimizing potato harvesting machinery.Practical applicationsDamage resulting from the mechanical harvesting process significantly impacts the quality and economic worth of the tubers. Currently, research on constructing a mechanical model of potatoes, treating them as viscoelastic plastic bodies, and integrating the collision process with potato soil separation devices is limited. Thus, the objective of this paper is to investigate the correlation between various test factors and potato damage via drop tests, and to establish a viscoelastic–plastic mechanical model. Additionally, the study further explored the correlation between model parameters and tuber damage, resulting in the establishment of a mathematical model for predicting the extent of damage. This study provides a theoretical basis for an in‐depth analysis of the collision damage mechanism of potato, and a technical reference for the design and optimization of potato harvesting machinery.

A self-regulation blades wind energy harvester system for self-powered wireless monitoring sensors

Using wind energy in the natural environment provides a promising solution for wireless sensor power supply for ecological, meteorological, environmental, and infrastructure monitoring. However, the uncertainty and disorder of natural wind restrict the further development of wind energy harvester systems and self-powered wireless sensor technology. Hence, this paper proposes a self-regulation blade wind energy harvester system (SBWEHS) for self-powered wireless monitoring sensors in remote field areas with power shortages. The system is mainly composed of three parts: wind harvesting mechanism, generator module, and energy storage module. The device can control the blade overlap ratio according to the wind speed while generating electricity to maximize the power coefficient. The system can control the blade’s closure in bad weather to protect the device. Based on the computational fluid dynamics technology of Ansys Fluent software, this study evaluated the impact of wind speed and blade overlap ratio on the two-stage blades. Experiments revealed that when the overlap ratio of the blades is fixed at 0.2 and the wind speed is set at 16 m/s, the maximum average power will reach 0.79 W, which fulfills the power requirements of wireless sensors. These results illustrate that the SBWEHS can effectively supply power for wireless monitoring sensors, especially in remote natural environments.

Non-smooth nonlocal mechanical diode

In this paper, we proposed a new mechanical diode with non-smooth and nonlocal elastic, which support a backflow of the input mechanical energy. It is composed of a nonlinear converter connecting with nonlocal bilinear springs and linear phononic crystal. The asymmetrical stiffness of bilinear springs can be utilized to periodically modulate the stiffness of converter, generate non-reciprocal propagation of mechanical waves, thereby decompose the excitation frequency into multiple sub-bands. Utilizing this characteristic of converter, during the forward propagation of mechanical diodes, it is possible to effectively surpass the cutoff frequency of phononic crystals, ensuring higher energy transmission efficiency and achieving wideband performance of mechanical diodes. Nonlocal connections induce a roton-like dispersion in the wave propagation, resulting in negative group velocities and partial energy backflow. The Runge-Kutta method is utilized to simulate wave propagation and verified by experimental. It is shown that the low-frequency impinging wave is rectified and nearly 100% contrast ratio is observed. Our work provide a new platform for mechanical wave manipulation and energy harvesting.

Quantitative Trait Locus Mapping for Plant Height and Branch Number in CCRI70 Recombinant Inbred Line Population of Upland Cotton (Gossypium hirsutum).

Upland cotton accounts for a high percentage (95%) of the world's cotton production. Plant height (PH) and branch number (BN) are two important agronomic traits that have an impact on improving the level of cotton mechanical harvesting and cotton yield. In this research, a recombinant inbred line (RIL) population with 250 lines developed from the variety CCRI70 was used for constructing a high-density genetic map and identification of quantitative trait locus (QTL). The results showed that the map harbored 8298 single nucleotide polymorphism (SNP) markers, spanning a total distance of 4876.70 centimorgans (cMs). A total of 69 QTLs for PH (9 stable) and 63 for BN (11 stable) were identified and only one for PH was reported in previous studies. The QTLs for PH and BN harbored 495 and 446 genes, respectively. Combining the annotation information, expression patterns and previous studies of these genes, six genes could be considered as potential candidate genes for PH and BN. The results could be helpful for cotton researchers to better understand the genetic mechanism of PH and BN development, as well as provide valuable genetic resources for cotton breeders to manipulate cotton plant architecture to meet future demands.

Comparative study on paddy harvesting technologies in Sylhet region

Mechanized paddy harvesting is currently limited in Bangladesh, but the pace of mechanization is increasing. Harvesting must be done on time to minimize losses and timely harvesting depends on the availability of harvesting machinery. The aim of this study was to find out the state of mechanized paddy harvesting technologies in Sylhet region over the last five years. The study was conducted in all upazilas under the Sylhet region to compare mechanized and manual paddy harvesting technologies. Structured questionnaire was used to collect data. The survey revealed the changes in mechanization status in 2022 compared to the previous four years. In the study area, the average paddy cultivable area was 0.91 million hectares. The pace of mechanized harvesting in Sylhet, Sunamganj, Habiganj, and Moulvibazar district were 31.49%, 24.41%, 19.59%, and 15.95%, respectively. On the basis of the provided data, from 2018 to 2022 the number of harvesting machines increased from 547 to 1852. The manual method, combine harvester, and reaper were used to harvest 76.20%, 21.90%, and 1.90% of the total projected area respectively in 2021-2022. The study revealed that combine harvester covered around 87.47% area than reaper. In 2022, among the 40 upazilas, the most machines were found at Nabiganj upazila in Habiganj district =106, and the fewest machines were found at Barlekha upazila in Moulvibazar district =10. The trend of manual paddy harvesting has declined in Sylhet region due to the increase in the number of harvesting machines. So, harvesting machineries are needed in this region to update paddy harvesting mechanization status.

Grain agriculture and the end of the fossil fuel era

First paragraphs: A great deal of attention is currently focused on how agriculture in highly industrialized coun­tries contributes to greenhouse gas (GHG) emis­sions, and how certain farming innovations might curb the emissions of nitrous oxide and methane and draw down carbon dioxide from the atmos­phere. What is not being discussed is how agricul­ture in general, and grain agriculture in particular, will need to change as society phases out its dependency on fossil fuels in order to achieve carbon (C) neutrality. Over the last century in the U.S., the number of farmers on the land declined by about 66%, in close proportion to the increase in average farm size (U.S. Department of Agriculture Economic Research Service [USDA ERS], n.d.). Integral to these trends has been the simplification of farming systems in which practices like fertility-generating rotations have been replaced with lower-diversity monocultures maintained by applications of fossil fuel–based fertilizers and pesticides (Crews & Peoples, 2004). Between fossil fuel–powered mechanization and fossil fuel–based input intensi­fication, the energy used by farmers to grow maize in the state of Nebraska is 99.7% from fossil fuels and 0.3% human labor (Grassini & Cassman, 2012; Pimentel & Pimentel, 2008). Even organic farming systems often require prodigious fossil fuel inputs with intensive tractor tillage, manure hauling, and mechanical harvesting (Smith et al., 2015). In con­trast to our modern grain-producing agroeecosys­tems, ancestral agroecosystems and natural ecosys­tems of all types—forests, grasslands, deserts, tundra—have remained productive for millennia with no fossil fuel inputs. In this commentary I explore the dependency of grain agriculture on fossil fuel use in the U.S. set in a global context, and approaches for reducing this dependency, including a shift to perennial polycultures that rely on ecological intensification in place of energy-intensive inputs. . . .