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Zhang L, Zuo S. The Significance of Lignocellulosic Raw Materials on the Pore Structure of Activated Carbons Prepared by Steam Activation. Molecules 2024; 29:3197. [PMID: 38999149 PMCID: PMC11243171 DOI: 10.3390/molecules29133197] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2024] [Revised: 06/30/2024] [Accepted: 07/03/2024] [Indexed: 07/14/2024] Open
Abstract
Five different lignocellulosic raw materials (coconut shells, Moso bamboo, sawtooth oak, Chinese fir, and Masson pine) were used to prepare activated carbons by steam activation at 850 °C to evaluate the effects of their structures on physical activation. The chemical compositions, botanic forms, and pore structures of the lignocellulose-based charcoal samples were systematically characterized by proximate and ultimate analyses, scanning electron microscopy, and mercury injection porosimetry. It was found that the rate of the activation reaction between charcoal and steam is determined by the porosity of the precursor. Pore structure results show that the steam activation of coconut shell and bamboo charcoals primarily produced micropores, thus yielding microporous activated carbon materials with just a few mesopores, even following a high burn-off of >66%. The steam activation of sawtooth oak charcoals produced mainly micropores at a low burn-off of <50% and both micropores and mesopores at a high burn-off of >50%. The steam activation of Chinese fir and Masson pine charcoals produced mainly mesopores at a burn-off of 0-80%. These mesopores were remarkably broadened to >20 nm on extending the activation time, resulting in a high vitamin B12 (VB12) adsorption capacity of ~530 mg/g. In conclusion, the raw lignocellulosic materials used as precursors have a decisive effect on the development of pore structures in activated carbon materials obtained through physical activation.
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Affiliation(s)
- Li Zhang
- International Innovation Center for Forest Chemicals and Materials, College of Chemical Engineering, Nanjing Forestry University, Nanjing 210037, China;
- Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, Nanjing Forestry University, Nanjing 210037, China
| | - Songlin Zuo
- International Innovation Center for Forest Chemicals and Materials, College of Chemical Engineering, Nanjing Forestry University, Nanjing 210037, China;
- Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, Nanjing Forestry University, Nanjing 210037, China
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2
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Luu RK, Buehler MJ. BioinspiredLLM: Conversational Large Language Model for the Mechanics of Biological and Bio-Inspired Materials. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024; 11:e2306724. [PMID: 38145334 PMCID: PMC10933662 DOI: 10.1002/advs.202306724] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Revised: 12/11/2023] [Indexed: 12/26/2023]
Abstract
The study of biological materials and bio-inspired materials science is well established; however, surprisingly little knowledge is systematically translated to engineering solutions. To accelerate discovery and guide insights, an open-source autoregressive transformer large language model (LLM), BioinspiredLLM, is reported. The model is finetuned with a corpus of over a thousand peer-reviewed articles in the field of structural biological and bio-inspired materials and can be prompted to recall information, assist with research tasks, and function as an engine for creativity. The model has proven that it is able to accurately recall information about biological materials and is further strengthened with enhanced reasoning ability, as well as with Retrieval-Augmented Generation (RAG) to incorporate new data during generation that can also help to traceback sources, update the knowledge base, and connect knowledge domains. BioinspiredLLM also has shown to develop sound hypotheses regarding biological materials design and remarkably so for materials that have never been explicitly studied before. Lastly, the model shows impressive promise in collaborating with other generative artificial intelligence models in a workflow that can reshape the traditional materials design process. This collaborative generative artificial intelligence method can stimulate and enhance bio-inspired materials design workflows. Biological materials are at a critical intersection of multiple scientific fields and models like BioinspiredLLM help to connect knowledge domains.
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Affiliation(s)
- Rachel K. Luu
- Laboratory for Atomistic and Molecular Mechanics (LAMM)Massachusetts Institute of Technology77 Massachusetts AvenueCambridgeMA02139USA
- Department of Materials Science and EngineeringMassachusetts Institute of Technology77 Massachusetts AvenueCambridgeMA02139USA
| | - Markus J. Buehler
- Laboratory for Atomistic and Molecular Mechanics (LAMM)Massachusetts Institute of Technology77 Massachusetts AvenueCambridgeMA02139USA
- Center for Computational Science and EngineeringSchwarzman College of ComputingMassachusetts Institute of Technology77 Massachusetts AvenueCambridgeMA02139USA
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3
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Sonego M, Morgenthal A, Fleck C, Pessan LA. Betholletia excelsa Fruit: Unveiling Toughening Mechanisms and Biomimetic Potential for Advanced Materials. Biomimetics (Basel) 2023; 8:509. [PMID: 37999150 PMCID: PMC10669686 DOI: 10.3390/biomimetics8070509] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2023] [Revised: 09/18/2023] [Accepted: 10/09/2023] [Indexed: 11/25/2023] Open
Abstract
Dry fruits and nutshells are biological capsules of outstanding toughness and strength with biomimetic potential to boost fiber-reinforced composites and protective structures. The strategies behind the Betholletia excelsa fruit mechanical performance were investigated with C-ring and compression tests. This last test was monitored with shearography and simulated with a finite element model. Microtomography and digital and scanning electron microscopy evaluated crack development. The fruit geometry, the preferential orientation of fibers involved in foam-like sclereid cells, promoted anisotropic properties but efficient energy dissipating mechanisms in different directions. For instance, the mesocarp cut parallel to its latitudinal section sustained higher forces (26.0 ± 2.8 kN) and showed higher deformation and slower crack propagation. The main toughening mechanisms are fiber deflection and fiber bridging and pullout, observed when fiber bundles are orthogonal to the crack path. Additionally, the debonding of fiber bundles oriented parallel to the crack path and intercellular cracks through sclereid and fiber cells created a tortuous path.
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Affiliation(s)
- Marilia Sonego
- Graduate Program in Materials Science and Engineering (PPGCEM), Federal University of São Carlos (UFSCar), São Carlos 13565-905, SP, Brazil;
- Institute of Mechanical Engineering, Federal University of Itajubá (UNIFEI), Itajubá 37500-903, MG, Brazil
| | - Anneke Morgenthal
- Materials Science and Engineering, Technische Universität Berlin, 10623 Berlin, Germany (C.F.)
| | - Claudia Fleck
- Materials Science and Engineering, Technische Universität Berlin, 10623 Berlin, Germany (C.F.)
| | - Luiz Antonio Pessan
- Graduate Program in Materials Science and Engineering (PPGCEM), Federal University of São Carlos (UFSCar), São Carlos 13565-905, SP, Brazil;
- Department of Materials Engineering, Federal University of São Carlos, São Carlos 13565-905, SP, Brazil
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Phungsara B, Jongpairojcosit N, Jearanaisilawong P. Finite element analysis of energy absorption mechanism of durian peel and durian thorns under compressive load. J Mech Behav Biomed Mater 2023; 145:106022. [PMID: 37453158 DOI: 10.1016/j.jmbbm.2023.106022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Revised: 07/06/2023] [Accepted: 07/08/2023] [Indexed: 07/18/2023]
Abstract
This study aims to investigate the energy absorption mechanism of durian peel under compression using finite element analysis. The durian peel comprises four substructures: thorn skin, thorn core, locule, and membrane. Their mechanical properties were measured experimentally and used as inputs for finite element models. Three-dimensional solid models of the durian peel were created and compared to the corresponding macroscopic responses. Good agreements between the experimental results and model predictions validate the measured properties. Energy analysis of the substructures shows that thorn skins and cores are the dominant components of energy absorption in durian peel under large deformation. Single thorn models with various aspect ratios were created to analyze their influence on energy absorption. The single thorn models were compressed at four angles of attack to capture the effect of peel curvature. The analysis shows that the aspect ratio of a single thorn that balances energy absorption at all angles of attack falls between 1 and 1.25, which is consistent with the experimentally measured values.
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Affiliation(s)
- Bundit Phungsara
- Department of Mechanical and Aerospace Engineering, Faculty of Engineering King Mongkut's University of Technology North Bangkok, 1518 Pracharat 1 Rd., Wongsawang, Bangsue, Bangkok, 10800, Thailand; Phranakhon Rajabhat University, 9 Changwattana Road, Bangkhen, Bangkok, 10220, Thailand
| | - Nadda Jongpairojcosit
- Phranakhon Rajabhat University, 9 Changwattana Road, Bangkhen, Bangkok, 10220, Thailand
| | - Petch Jearanaisilawong
- Department of Mechanical and Aerospace Engineering, Faculty of Engineering King Mongkut's University of Technology North Bangkok, 1518 Pracharat 1 Rd., Wongsawang, Bangsue, Bangkok, 10800, Thailand.
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Lazarus BS, Leung V, Luu RK, Wong MT, Ruiz-Pérez S, Barbosa WT, Bezerra WBA, Barbosa JDV, Meyers MA. Jackfruit: Composition, structure, and progressive collapsibility in the largest fruit on the Earth for impact resistance. Acta Biomater 2023; 166:430-446. [PMID: 37121367 DOI: 10.1016/j.actbio.2023.04.040] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Revised: 04/17/2023] [Accepted: 04/26/2023] [Indexed: 05/02/2023]
Abstract
The jackfruit is the largest fruit on the Earth, reaching upwards of 35 kg and falling from heights of 25 m. To survive such high energy impacts, it has evolved a unique layered configuration with a thorny exterior and porous tubular underlayer. During compression, these layers exhibit a progressive collapse mechanism where the tubules are first to deform, followed by the thorny exterior, and finally the mesocarp layer in between. The thorns are composed of lignified bundles which run longitudinally from the base of the thorn to the tip and are embedded in softer parenchymal cells, forming a fiber reinforced composite. The mesocarp contains more lignin than any of the other layers while the core appears to contain more pectin giving rise to variations in compressive and viscoelastic properties between the layers. The surface thorns provide a compelling impact-resistant feature for bioinspiration, with a cellular structure that can withstand large deformation without failing and wavy surface features which densify during compression without fracturing. Even the conical shape of the thorns is valuable, presenting a gradually increasing surface area during axial collapse. A simplified model of this mechanism is put forward to describe the force response of these features. The thorns also distribute damage laterally during impact and deflect cracks along their interstitial valleys. These phenomena were observed in 3D printed, jackfruit-inspired designs which performed markedly better than control prints with the same mass. STATEMENT OF SIGNIFICANCE: Many biological materials have evolved remarkable structures that enhance their mechanical performance and serve as sources of inspiration for engineers. Plants are often overlooked in this regard yet certain botanical components, like nuts and fruit, have shown incredible potential as blueprints for improved impact resistant designs. The jackfruit is the largest fruit on Earth and generates significant falling impact energies. Here, we explore the jackfruit's structure and its mechanical capabilities for the first time. The progressive failure imparted by its multilayered design and the unique collapse mode of the surface thorns are identified as key mechanisms for improving the fruit's impact resistance. 3D printing is used to show that these structure-property benefits can be successfully transferred to engineering materials.
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Affiliation(s)
- Benjamin S Lazarus
- Materials Science and Engineering Program, University of California San Diego, USA.
| | - Victor Leung
- Department of Mechanical and Aerospace Engineering, University of California San Diego, USA
| | - Rachel K Luu
- Department of Mechanical and Aerospace Engineering, University of California San Diego, USA; Department of Materials Science and Engineering, Massachusetts Institute of Technology, USA
| | - Matthew T Wong
- Department of Nanoengineering, University of California San Diego, USA
| | - Samuel Ruiz-Pérez
- Facultad de Ciencias, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Willams T Barbosa
- Department of Materials, University Center SENAI CIMATEC, Salvador, Brazil
| | - Wendell B Almeida Bezerra
- Department of Materials Science, Military Institute of Engineering-IME, Rio de Janeiro 22290270, Brazil
| | | | - Marc A Meyers
- Materials Science and Engineering Program, University of California San Diego, USA; Department of Mechanical and Aerospace Engineering, University of California San Diego, USA; Department of Nanoengineering, University of California San Diego, USA
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Abulikemu G, Wahman DG, Sorial GA, Nadagouda M, Stebel EK, Womack EA, Smith SJ, Kleiner EJ, Gray BN, Taylor RD, Gastaldo CX, Pressman JG. Role of grinding method on granular activated carbon characteristics. CARBON TRENDS 2023; 11:1-12. [PMID: 37234684 PMCID: PMC10208277 DOI: 10.1016/j.cartre.2023.100261] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
A coconut shell (AC1230CX) and a bituminous coal based (F400) granular activated carbon (GAC) were ground with mortar and pestle (MP), a blender, and a bench-scale ball milling unit (BMU). Blender was the most time-efficient for particle size reduction. Four size fractions ranging from 20 × 40 to 200 × 325 were characterized along with the bulk GACs. Compared to bulk GACs, F400 blender and BMU 20 × 40 fractions decreased in specific surface area (SSA, -23% and -31%, respectively) while smaller variations (-14% to 5%) occurred randomly for AC1230CX ground fractions. For F400, the blender and BMU size fraction dependencies were attributed to the combination of (i) radial trends in the F400 particle properties and (ii) importance of shear (outer layer removal) versus shock (particle fracturing) size reduction mechanisms. Compared to bulk GACs, surface oxygen content (At%-O1s) increased up to 34% for the F400 blender and BMU 20 × 40 fractions, whereas all AC1230CX ground fractions, except for the blender 100 × 200 and BMU 60 × 100 and 100 × 200 fractions, showed 25-29% consistent increases. The At%-O1s gain was attributed to (i) radial trends in F400 properties and (ii) oxidization during grinding, both of which supported the shear mechanism of mechanical grinding. Relatively small to insignificant changes in point of zero charge (pHPZC) and crystalline structure showed similar trends with the changes in SSA and At%-O1s. The study findings provide guidance for informed selection of grinding methods based on GAC type and target particle sizes to improve the representativeness of adsorption studies conducted with ground GAC, such as rapid small-scale column tests. When GACs have radial trends in their properties and when the target size fraction only includes larger particle sizes, manual grinding is recommended.
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Affiliation(s)
- Gulizhaer Abulikemu
- Pegasus Technical Services, Inc., Cincinnati, OH 45219, USA
- Department of Chemical and Environmental Engineering, University of Cincinnati, Cincinnati, OH 45221, USA
| | - David G. Wahman
- Center for Environmental Solutions and Emergency Response, U.S. Environmental Protection Agency, 26 W. Martin Luther King Dr., Cincinnati, OH 45268, USA
| | - George A. Sorial
- Department of Chemical and Environmental Engineering, University of Cincinnati, Cincinnati, OH 45221, USA
| | - Mallikarjuna Nadagouda
- Center for Environmental Solutions and Emergency Response, U.S. Environmental Protection Agency, 26 W. Martin Luther King Dr., Cincinnati, OH 45268, USA
| | - Eva K. Stebel
- Pegasus Technical Services, Inc., Cincinnati, OH 45219, USA
- Department of Chemical and Environmental Engineering, University of Cincinnati, Cincinnati, OH 45221, USA
| | - Erika A. Womack
- Oak Ridge Institute for Science and Education, Oak Ridge, TN 37830, USA
- Procter and Gamble Company, Cincinnati, OH 45202, USA
| | - Samantha J. Smith
- Center for Environmental Solutions and Emergency Response, U.S. Environmental Protection Agency, 26 W. Martin Luther King Dr., Cincinnati, OH 45268, USA
| | - Eric J. Kleiner
- Center for Environmental Solutions and Emergency Response, U.S. Environmental Protection Agency, 26 W. Martin Luther King Dr., Cincinnati, OH 45268, USA
| | - Brooke N. Gray
- Department of Chemical and Environmental Engineering, University of Cincinnati, Cincinnati, OH 45221, USA
- Oak Ridge Institute for Science and Education, Oak Ridge, TN 37830, USA
| | - Rose D. Taylor
- Oak Ridge Institute for Science and Education, Oak Ridge, TN 37830, USA
- Department of Civil and Environmental Engineering, University of Maryland, College Park, MD 20742, USA
| | - Cameron X. Gastaldo
- Department of Chemical and Environmental Engineering, University of Cincinnati, Cincinnati, OH 45221, USA
- Oak Ridge Institute for Science and Education, Oak Ridge, TN 37830, USA
| | - Jonathan G. Pressman
- Center for Environmental Solutions and Emergency Response, U.S. Environmental Protection Agency, 26 W. Martin Luther King Dr., Cincinnati, OH 45268, USA
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Mazumder S, Zhang N. Cellulose-Hemicellulose-Lignin Interaction in the Secondary Cell Wall of Coconut Endocarp. Biomimetics (Basel) 2023; 8:biomimetics8020188. [PMID: 37218775 DOI: 10.3390/biomimetics8020188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Revised: 04/24/2023] [Accepted: 04/26/2023] [Indexed: 05/24/2023] Open
Abstract
The coconut shell consists of three distinct layers: the skin-like outermost exocarp, the thick fibrous mesocarp, and the hard and tough inner endocarp. In this work, we focused on the endocarp because it features a unique combination of superior properties, including low weight, high strength, high hardness, and high toughness. These properties are usually mutually exclusive in synthesized composites. The microstructures of the secondary cell wall of the endocarp at the nanoscale, in which cellulose microfibrils are surrounded by hemicellulose and lignin, were generated. All-atom molecular dynamics simulations with PCFF force field were conducted to investigate the deformation and failure mechanisms under uniaxial shear and tension. Steered molecular dynamics simulations were carried out to study the interaction between different types of polymer chains. The results demonstrated that cellulose-hemicellulose and cellulose-lignin exhibit the strongest and weakest interactions, respectively. This conclusion was further validated against the DFT calculations. Additionally, through shear simulations of sandwiched polymer models, it was found that cellulose-hemicellulose-cellulose exhibits the highest strength and toughness, while cellulose-lignin-cellulose shows the lowest strength and toughness among all tested cases. This conclusion was further confirmed by uniaxial tension simulations of sandwiched polymer models. It was revealed that hydrogen bonds formed between the polymer chains are responsible for the observed strengthening and toughening behaviors. Additionally, it was interesting to note that failure mode under tension varies with the density of amorphous polymers located between cellulose bundles. The failure mode of multilayer polymer models under tension was also investigated. The findings of this work could potentially provide guidelines for the design of coconut-inspired lightweight cellular materials.
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Affiliation(s)
- Sharmi Mazumder
- Department of Mechanical Engineering, Baylor University, Waco, TX 76706, USA
| | - Ning Zhang
- Department of Mechanical Engineering, Baylor University, Waco, TX 76706, USA
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Sun J, Wang Z. Hierarchical levels of the ginkgo seed shell. Sci Bull (Beijing) 2023; 68:376-378. [PMID: 36754761 DOI: 10.1016/j.scib.2023.02.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- Jing Sun
- Department of Mechanical Engineering, City University of Hong Kong, Hong Kong, China
| | - Zuankai Wang
- Department of Mechanical Engineering, The Hong Kong Polytechnic University, Hong Kong, China.
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Lin S, Zhang Y, Luo L, Huang M, Cao H, Hu J, Sun C, Chen J. Visualization and quantification of coconut using advanced computed tomography postprocessing technology. PLoS One 2023; 18:e0282182. [PMID: 36827442 PMCID: PMC9956593 DOI: 10.1371/journal.pone.0282182] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Accepted: 02/09/2023] [Indexed: 02/26/2023] Open
Abstract
INTRODUCTION Computed tomography (CT) is a non-invasive examination tool that is widely used in medicine. In this study, we explored its value in visualizing and quantifying coconut. MATERIALS AND METHODS Twelve coconuts were scanned using CT for three months. Axial CT images of the coconuts were obtained using a dual-source CT scanner. In postprocessing process, various three-dimensional models were created by volume rendering (VR), and the plane sections of different angles were obtained through multiplanar reformation (MPR). The morphological parameters and the CT values of the exocarp, mesocarp, endocarp, embryo, bud, solid endosperm, liquid endosperm, and coconut apple were measured. The analysis of variances was used for temporal repeated measures and linear and non-linear regressions were used to analyze the relationship between the data. RESULTS The MPR images and VR models provide excellent visualization of the different structures of the coconut. The statistical results showed that the weight of coconut and liquid endosperm volume decreased significantly during the three months, while the CT value of coconut apple decreased slightly. We observed a complete germination of a coconut, its data showed a significant negative correlation between the CT value of the bud and the liquid endosperm volume (y = -2.6955x + 244.91; R2 = 0.9859), and a strong positive correlation between the height and CT value of the bud (y = 1.9576 ln(x) -2.1655; R2 = 0.9691). CONCLUSION CT technology can be used for visualization and quantitative analysis of the internal structure of the coconut, and some morphological changes and composition changes of the coconut during the germination process were observed during the three-month experiment. Therefore, CT is a potential tool for analyzing coconuts.
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Affiliation(s)
- Shenghuang Lin
- Haikou Affiliated Hospital of Central South University Xiangya School of Medicine, Haikou, China
| | - Yu Zhang
- College of Computer Science and Technology, Hainan University, Haikou, China
| | - Li’an Luo
- Siemens Healthineers, Guangzhou, China
| | - Mengxing Huang
- College of Information and Communication Engineering, Hainan University, Haikou, China
| | - Hongxing Cao
- Coconut Research Institute, Chinese Academy of Tropical Agricultural Sciences, Wenchang, Hainan, People’s Republic of China
| | - Jinyue Hu
- Haikou Affiliated Hospital of Central South University Xiangya School of Medicine, Haikou, China
| | - Chengxu Sun
- Coconut Research Institute, Chinese Academy of Tropical Agricultural Sciences, Wenchang, Hainan, People’s Republic of China
- * E-mail: (JC); (CS)
| | - Jing Chen
- Haikou Affiliated Hospital of Central South University Xiangya School of Medicine, Haikou, China
- * E-mail: (JC); (CS)
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Effect of lignocellulosic composition of Reutealis trisperma waste on nanocrystalline cellulose properties. BIOCATALYSIS AND AGRICULTURAL BIOTECHNOLOGY 2022. [DOI: 10.1016/j.bcab.2022.102516] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Antreich SJ, Huss JC, Xiao N, Singh A, Gierlinger N. The walnut shell network: 3D visualisation of symplastic and apoplastic transport routes in sclerenchyma tissue. PLANTA 2022; 256:49. [PMID: 35881249 PMCID: PMC9325819 DOI: 10.1007/s00425-022-03960-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Accepted: 07/06/2022] [Indexed: 05/16/2023]
Abstract
High symplastic connectivity via pits was linked to the lignification of the developing walnut shell. With maturation, this network lessened, whereas apoplastic intercellular space remained and became relevant for shell drying. The shell of the walnut (Juglans regia) sclerifies within several weeks. This fast secondary cell wall thickening and lignification of the shell tissue might need metabolites from the supporting husk tissue. To reveal the transport capacity of the walnut shell tissue and its connection to the husk, we visualised the symplastic and apoplastic transport routes during shell development by serial block face-SEM and 3D reconstruction. We found an extensive network of pit channels connecting the cells within the shell tissue, but even more towards the husk tissue. Each pit channel ended in a pit field, which was occupied by multiple plasmodesmata passing through the middle lamella. During shell development, secondary cell wall formation progressed towards the interior of the cell, leaving active pit channels open. In contrast, pit channels, which had no plasmodesmata connection to a neighbouring cell, got filled by cellulose layers from the inner cell wall lamellae. A comparison with other nut species showed that an extended network during sclerification seemed to be linked to high cell wall lignification and that the connectivity between cells got reduced with maturation. In contrast, intercellular spaces between cells remained unchanged during the entire sclerification process, allowing air and water to flow through the walnut shell tissue when mature. The connectivity between inner tissue and environment was essential during shell drying in the last month of nut development to avoid mould formation. The findings highlight how connectivity and transport work in developing walnut shell tissue and how finally in the mature state these structures influence shell mechanics, permeability, conservation and germination.
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Affiliation(s)
- Sebastian J Antreich
- Institute of Biophysics, Department of Nanobiotechnology, University of Natural Resources and Life Sciences, 1190, Vienna, Austria.
| | - Jessica C Huss
- Institute of Biophysics, Department of Nanobiotechnology, University of Natural Resources and Life Sciences, 1190, Vienna, Austria
| | - Nannan Xiao
- Institute of Biophysics, Department of Nanobiotechnology, University of Natural Resources and Life Sciences, 1190, Vienna, Austria
| | - Adya Singh
- Institute of Biophysics, Department of Nanobiotechnology, University of Natural Resources and Life Sciences, 1190, Vienna, Austria
| | - Notburga Gierlinger
- Institute of Biophysics, Department of Nanobiotechnology, University of Natural Resources and Life Sciences, 1190, Vienna, Austria
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Sonego M, Sciuti VF, Vargas R, Canto RB, Pessan LA. Composite design bioinspired by the mesocarp of Brazil nut ( Bertholletia excelsa). BIOINSPIRATION & BIOMIMETICS 2022; 17:046011. [PMID: 35552274 DOI: 10.1088/1748-3190/ac6f37] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Accepted: 05/12/2022] [Indexed: 06/15/2023]
Abstract
The mesocarp ofBertholletia excelsais a rich source of inspiration for strong, stiff and damage-tolerant composites. The bioinspired composites developed here are composed of an epoxy matrix with a 3D printed polylactic acid reinforced with 30% of carbon fiber (PLA-30CF) inspired in fibers, and syntactic foam inspired by sclereids. Monotonic and cyclic four-point bending tests and compact tension fracture toughness tests were carried out assisted by digital image correlation (DIC) to evaluate flexural properties, damage tolerance, and theR-curve of the composite. Its microstructure and fracture surface were analyzed by scanning electron microscopy. The mechanical performance of the bioinspired composite is promising: density of 1.0 g cm-3, flexural apparent elastic modulus of 1.6 GPa, and flexural strength six times higher than the neat epoxy, i.e. 17 MPa. Although the PLA-30CF printed structure led to a risingR-curve, the syntactic foam needs optimization to have a synergistic effect.
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Affiliation(s)
- M Sonego
- Graduate Program in Materials Science and Engineering (PPGCEM), Federal University of São Carlos (UFSCar), São Carlos, SP, Brazil
- Mechanical Engineering Institute, Federal University of Itajubá (UNIFEI), Itajubá, MG, Brazil
| | - V F Sciuti
- Graduate Program in Materials Science and Engineering (PPGCEM), Federal University of São Carlos (UFSCar), São Carlos, SP, Brazil
- Department of Materials Engineering (DEMa), Federal University of São Carlos (UFSCar), São Carlos, SP, Brazil
| | - R Vargas
- Graduate Program in Materials Science and Engineering (PPGCEM), Federal University of São Carlos (UFSCar), São Carlos, SP, Brazil
- Université Paris-Saclay, CentraleSupélec, ENS Paris-Saclay, CNRS, LMPS - Laboratoire de Mécanique Paris-Saclay, Gif-sur-Yvette, France
| | - R B Canto
- Graduate Program in Materials Science and Engineering (PPGCEM), Federal University of São Carlos (UFSCar), São Carlos, SP, Brazil
- Department of Materials Engineering (DEMa), Federal University of São Carlos (UFSCar), São Carlos, SP, Brazil
| | - L A Pessan
- Graduate Program in Materials Science and Engineering (PPGCEM), Federal University of São Carlos (UFSCar), São Carlos, SP, Brazil
- Department of Materials Engineering (DEMa), Federal University of São Carlos (UFSCar), São Carlos, SP, Brazil
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Orientation-dependent micromechanical behavior of nacre: In situ TEM experiments and finite element simulations. Acta Biomater 2022; 147:120-128. [PMID: 35609803 DOI: 10.1016/j.actbio.2022.05.033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Revised: 04/07/2022] [Accepted: 05/17/2022] [Indexed: 11/22/2022]
Abstract
Nacre's superior mechanical properties and failure behavior are strongly orientation-dependent due to its brick-and-mortar microstructure. In this work, the anisotropic microscopic deformation and the resulting macroscopic mechanical properties are evaluated under different loading conditions. Our in situ transmission electron microscopy deformation experiments and finite element simulations reveal that nacre possesses enhanced indentation resistance along the direction normal to the tablets through delocalization of indentation-induced deformation by taking advantage of its layered structure. In addition, nacre's ability to recover from large deformations is observed. We study the strong loading direction dependence of nacre's macroscopic mechanical properties and elucidate the underlying microscopic deformation patterns in the tablets and the soft matrix. Particularly, its performance along the transverse direction is optimized to withstand the loading conditions in nature. We show the importance of the vertical matrix for the initial stiffness and fracture toughness of the composite. These findings provide guidelines for designing nacre-inspired artificial composites with enhanced mechanical properties. STATEMENT OF SIGNIFICANCE: Nacre is widely recognized as an excellent structural model for designing bio-inspired tough and strong artificial composites. Due to its brick-and-mortar microstructure, it exhibits loading direction-dependent mechanical behavior. In this contribution, we investigate the macroscopic mechanical properties and microscopic deformation behavior of nacre under different loading conditions by means of in situ TEM deformation tests and FE simulations. It is found that effective elastic moduli and microscopic deformation strongly depend on the loading direction. The organic matrix is highly deformable. The indentation resistance along the direction normal to tablets is enhanced via deformation delocalization. Our quantitative and qualitative results provide guidelines on optimizing the mechanical properties of nacre-inspired novel composites.
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14
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Ghimire A, Chen PY. Seed protection strategies of the brainy Elaeocarpus ganitrus endocarp: Gradient motif yields fracture tolerance. Acta Biomater 2022; 138:430-442. [PMID: 34728425 DOI: 10.1016/j.actbio.2021.10.050] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2021] [Revised: 10/07/2021] [Accepted: 10/20/2021] [Indexed: 12/26/2022]
Abstract
Be it animals or plants, most of the organism's offspring come into existence after their embryos develop inside a protective shell. In plants, these hard protective shells are called endocarps. They serve the function of nourishing and protecting the seeds from external mechanical damage. Through evolution, endocarps of plants have developed various structural strategies to protect the enclosed seeds from external threats, and these strategies can vary according to the habitat or lifestyle of a particular plant. One such intriguing hard plant shell is the endocarp of the Elaeocarpus ganitrus fruit. It mostly grows in South Asia's mountainous forests, and its endocarps are known in the local communities as unbreakable and everlasting prayer beads. We report an in-depth investigation on microstructure, tomography, and mechanical properties to cast light on its performance and the underlying structure-property relation. The 3D structural quantifications by micro-CT demonstrate that the endocarp has gradient microarchitecture. In addition, the endocarp also exhibits gradient hardness and stiffness. The toughening mechanisms arising from the layered cellular structure enable the endocarps to withstand higher loads up to 5000 N before they fracture. Our findings provide experimental evidence of outstanding fracture tolerance and seed protection strategies developed by Elaeocarpus ganitrus endocarp that encourage the design of synthetic fracture tolerant structures. STATEMENT OF SIGNIFICANCE: Endocarps are low-density plant shells that exhibit remarkable fracture resistance and energy absorption when they encounter impact by falling from high trees and prolonged compression and abrasion by the predators. Such outstanding mechanical performance originates through structural design strategies developed to protect their seeds. Here we demonstrate previously undiscovered structural features and mechanical properties of Elaeocarpus ganitrus endocarp. We scrutinize the microstructure using high-resolution x-ray tomography scans and the 3D structural quantifications reveal a gradient microstructure which is in agreement with the gradient hardness and stiffness. The multiscale hierarchical structures combined with the gradient motif yield impressive fracture tolerance in Elaeocarpus ganitrus endocarp. These findings advance the knowledge of the structure-property relation in hard plant shells, and the procured structural design strategies can be utilized to design fracture-resistant structures.
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15
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Huss JC, Gierlinger N. Functional packaging of seeds. THE NEW PHYTOLOGIST 2021; 230:2154-2163. [PMID: 33629369 PMCID: PMC8252473 DOI: 10.1111/nph.17299] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Accepted: 02/16/2021] [Indexed: 05/28/2023]
Abstract
The encapsulation of seeds in hard coats and fruit walls (pericarp layers) fulfils protective and dispersal functions in many plant families. In angiosperms, packaging structures possess a remarkable range of different morphologies and functionalities, as illustrated by thermo and hygro-responsive seed pods and appendages, as well as mechanically strong and water-impermeable shells. Key to these different functionalities are characteristic structural arrangements and chemical modifications of the underlying sclerenchymatous tissues. Although many ecological aspects of hard seed encapsulation have been well documented, a detailed understanding of the relationship between tissue structure and function only recently started to emerge, especially in the context of environmentally driven fruit opening and seed dispersal (responsive encapsulations) and the outstanding durability of some seed coats and indehiscent fruits (static encapsulations). In this review, we focus on the tissue properties of these two systems, with particular consideration of water interactions, mechanical resistance, and force generation. Common principles, as well as unique adaptations, are discussed in different plant species. Understanding how plants integrate a broad range of functions and properties for seed protection during storage and dispersal plays a central role for seed conservation, population dynamics, and plant-based material developments.
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Affiliation(s)
- Jessica C. Huss
- Department of NanobiotechnologyInstitute of BiophysicsUniversity of Natural Resources and Life Sciences (BOKU) ViennaMuthgasse 11/IIVienna1900Austria
| | - Notburga Gierlinger
- Department of NanobiotechnologyInstitute of BiophysicsUniversity of Natural Resources and Life Sciences (BOKU) ViennaMuthgasse 11/IIVienna1900Austria
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16
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Sonego M, Madia M, Eder M, Fleck C, Pessan LA. Microstructural features influencing the mechanical performance of the Brazil nut (Bertholletia excelsa) mesocarp. J Mech Behav Biomed Mater 2021; 116:104306. [PMID: 33513460 DOI: 10.1016/j.jmbbm.2020.104306] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 12/26/2020] [Accepted: 12/29/2020] [Indexed: 11/17/2022]
Abstract
Brazil nut (Bertholletia excelsa) fruits are capable of resisting high mechanical forces when released from trees as tall as 50 m, as well as during animal dispersal by sharp-teethed rodents. Thick mesocarp plays a crucial part in seed protection. We investigated the role of microstructure and how sclereids, fibers, and voids affect nutshell performance using compression, tensile and fracture toughness tests. Fractured specimens were analyzed through scanning electron microscopy (SEM) and microtomography (microCT). Mesocarp showed high deformability (strain at max. stress of ~30%) under compression loading, a critical tensile strength of ~24.9 MPa, a Weibull modulus of ~3, and an elastic modulus of ~2 GPa in the tensile test. The fracture toughness, estimated through the work of fracture of SENB tests, reached ~2 kJ/m2. The thick and strong walls of mesocarp cells, with a weaker boundary between them (compound middle lamella), promote a tortuous intercellular crack path. Several toughening mechanisms, such as crack deflection, breaking of fiber bundles, fiber pullout and bridging as well as crack branching, occur depending on how fiber bundles and voids are oriented.
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Affiliation(s)
- Marilia Sonego
- Graduate Program in Materials Science and Engineering (PPGCEM), Federal University of São Carlos (UFSCar), São Carlos, 13.565-905, SP, Brazil.
| | - Mauro Madia
- Bundesanstalt für Materialforschung und-prüfung (BAM), 12205, Berlin, Germany
| | - Michaela Eder
- Max-Planck-Institute of Colloids and Interfaces, Department of Biomaterials, Am Mühlenberg 1, Potsdam, 14476, Germany
| | - Claudia Fleck
- Materials Science & Engineering, Technische Universität Berlin, Berlin, 10623, Germany
| | - Luiz A Pessan
- Graduate Program in Materials Science and Engineering (PPGCEM), Federal University of São Carlos (UFSCar), São Carlos, 13.565-905, SP, Brazil; Department of Materials Engineering, Federal University of São Carlos, via Washington Luiz, Km 235, 13565-905 São Carlos, SP, Brazil
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17
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Zimmermann EA, Fiedler IAK, Busse B. Breaking new ground in mineralized tissue: Assessing tissue quality in clinical and laboratory studies. J Mech Behav Biomed Mater 2020; 113:104138. [PMID: 33157423 DOI: 10.1016/j.jmbbm.2020.104138] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Revised: 09/15/2020] [Accepted: 10/07/2020] [Indexed: 02/07/2023]
Abstract
Mineralized tissues, such as bone and teeth, have extraordinary mechanical properties of both strength and toughness. This mechanical behavior originates from deformation and fracture resistance mechanisms in their multi-scale structure. The term quality describes the matrix composition, multi-scale structure, remodeling dynamics, water content, and micro-damage accumulation in the tissue. Aging and disease result in changes in the tissue quality that may reduce strength and toughness and lead to elevated fracture risk. Therefore, the capability to measure the quality of mineralized tissues provides critical information on disease progression and mechanical integrity. Here, we provide an overview of clinical and laboratory-based techniques to assess the quality of mineralized tissues in health and disease. Current techniques used in clinical settings include radiography-based (radiographs, dual energy x-ray absorptiometry, EOS) and x-ray tomography-based methods (high resolution peripheral quantitative computed tomography, cone beam computed tomography). In the laboratory, tissue quality can be investigated in ex vivo samples with x-ray imaging (micro and nano-computed tomography, x-ray microscopy), electron microscopy (scanning/transmission electron imaging (SEM/STEM), backscattered scanning electron microscopy, Focused Ion Beam-SEM), light microscopy, spectroscopy (Raman spectroscopy and Fourier transform infrared spectroscopy) and assessment of mechanical behavior (mechanical testing, fracture mechanics and reference point indentation). It is important for clinicians and basic science researchers to be aware of the techniques available in different types of research. While x-ray imaging techniques translated to the clinic have provided exceptional advancements in patient care, the future challenge will be to incorporate high-resolution laboratory-based bone quality measurements into clinical settings to broaden the depth of information available to clinicians during diagnostics, treatment and management of mineralized tissue pathologies.
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Affiliation(s)
| | - Imke A K Fiedler
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Björn Busse
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
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18
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Sonego M, Fleck C, Pessan LA. Hierarchical levels of organization of the Brazil nut mesocarp. Sci Rep 2020; 10:6786. [PMID: 32321974 PMCID: PMC7176704 DOI: 10.1038/s41598-020-62245-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Accepted: 12/26/2019] [Indexed: 11/08/2022] Open
Abstract
Aiming to understand Nature´s strategies that inspire new composite materials, the hierarchical levels of organization of the Brazil nut (Bertholletia excelsa) mesocarp were investigated. Optical microscopy, scanning electron microscopy (SEM), microtomography (MicroCT) and small-angle X-ray scattering (SAXS) were used to deeply describe the cellular and fibrillary levels of organization. The mesocarp is the middle layer of the fruit which has developed several strategies to avoid its opening and protect its seed. Fibers have a different orientation in the three layers of the mesocarp, what reduces the anisotropy of the structure. Sclereids cells with thick cell walls fill the spaces between the fibers resembling a foam-filled structural composite. The mesocarp has several tubular channels and fractured surfaces which may work as sites for crack trapping and increase toughness. The thick and lignified cell wall of sclereids and fibers and the weak interface between cells can promote a longer and tortuous intercellular crack path. Additionally, fibers with high strength and stiffness due to microfibrils oriented along the main cell axis (µ = 0° to 17°) were identified in the innermost layer of the mesocarp. Such an understanding of each hierarchical level can inspire the development of new cellular composites with improved mechanical behavior.
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Affiliation(s)
- Marilia Sonego
- Department of Materials Engineering, Federal University of São Carlos, via Washington Luiz, Km 235, 13565-905, São Carlos, SP, Brazil.
- Graduate Program in Materials Science and Engineering (PPGCEM), Federal University of São Carlos (UFSCar), via Washington Luiz, Km 235, 13565-905, São Carlos, SP, Brazil.
| | - Claudia Fleck
- Materials Science and Engineering, Technische Universität Berlin, Berlin, 10623, Germany
| | - Luiz Antonio Pessan
- Department of Materials Engineering, Federal University of São Carlos, via Washington Luiz, Km 235, 13565-905, São Carlos, SP, Brazil
- Graduate Program in Materials Science and Engineering (PPGCEM), Federal University of São Carlos (UFSCar), via Washington Luiz, Km 235, 13565-905, São Carlos, SP, Brazil
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19
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Mechanical properties and failure deformation mechanisms of yak horn under quasi-static compression and dynamic impact. J Mech Behav Biomed Mater 2020; 107:103753. [PMID: 32364949 DOI: 10.1016/j.jmbbm.2020.103753] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2019] [Revised: 01/17/2020] [Accepted: 03/21/2020] [Indexed: 11/22/2022]
Abstract
In the natural environment, the horns of yak possess remarkable structural mechanical properties to protect the head from injury. In this paper, quasi-static compression and dynamic impact tests were conducted on yak horn in different regions under axial and lateral conditions to evaluate mechanical properties such as elastic modulus, ultimate strength and energy absorption. Meanwhile, the failure deformation mechanism under both low and high strain rates is explored. Moreover, experimental analysis of the correlation among mechanical properties, sampling position, strain rate and loading direction was conducted. Fracture surface of horn was observed with the scanning electron microscope (SEM). Research data demonstrate that specific energy absorption and mechanical properties are correlated with sampling position. Under quasi-static compression and dynamic impact, clear anisotropy behavior of horn was observed, which is evidently reflected in the load-displacement curve. Mechanical properties such as elastic modulus and ultimate strength are different under quasi-static compression and dynamic impact. The failure mode of lamellar buckling and delamination existed in the axial failure process. Brittle fracture and extrusion densification occurred more frequently in the process of lateral failure.
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20
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Ha NS, Lu G, Shu D, Yu TX. Mechanical properties and energy absorption characteristics of tropical fruit durian (Durio zibethinus). J Mech Behav Biomed Mater 2020; 104:103603. [PMID: 31929094 DOI: 10.1016/j.jmbbm.2019.103603] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Revised: 11/30/2019] [Accepted: 12/20/2019] [Indexed: 11/18/2022]
Abstract
The paper presents for the first time the material properties and energy absorption capacity of durian shells with an attempt to use as an alternative sustainable material and mimic their structural characteristics to design a bio-inspired structure for protective packaging applications. A series of quasi-static compression tests were carried out to determine Young's modulus and bioyield stress of the durian shells as well as their energy absorption capacity. The mesocarp layers and thorns are interesting parts for investigating their energy absorption characteristics because they play an important role in protecting the flesh of durians during their drop impact onto the ground. The mesocarp layers of the shell were subjected to axial and lateral compression while the thorn specimens were compressed under axial loading with an increasing number of thorns. The results showed that the densification strain, plateau stress and specific energy absorption of the mesocarp layer under lateral loading is higher than that under axial loading. Furthermore, the compression tests on the thorns demonstrated that an increase in the number of thorns helped to absorb more energy and the specific energy absorption of the thorns was nearly two times higher than that of the mesocarp layer under the axial loading. In addition, the cyclic loading of the thorns showed that the extent of reversibility of deformation in the thorns decreases from 32% at the first cycle to around 10% at the 9th-cycle. Finally, the microstructure of the thorn and mesocarp layer was investigated to explain the experimental observation. The results indicated that the spherical shape associated with the thorns and mesocarp materials displayed an excellent energy absorption efficiency that can be mimicked to design an effective bio-inspired absorber for packing applications.
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Affiliation(s)
- Ngoc San Ha
- Department of Mechanical and Product Design Engineering, Faculty of Science, Engineering & Technology, Swinburne University of Technology, Hawthorn, VIC, 3122, Australia
| | - Guoxing Lu
- Department of Mechanical and Product Design Engineering, Faculty of Science, Engineering & Technology, Swinburne University of Technology, Hawthorn, VIC, 3122, Australia.
| | - DongWei Shu
- School of Mechanical & Aerospace Engineering, Nanyang Technological University, 639798, Singapore
| | - T X Yu
- Department of Mechanical and Aerospace Engineering, The Hong Kong University of Science and Technology, Kowloon, Hong Kong
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21
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Schmier S, Hosoda N, Speck T. Hierarchical Structure of the Cocos nucifera (Coconut) Endocarp: Functional Morphology and its Influence on Fracture Toughness. Molecules 2020; 25:molecules25010223. [PMID: 31935819 PMCID: PMC6983247 DOI: 10.3390/molecules25010223] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Revised: 12/23/2019] [Accepted: 12/27/2019] [Indexed: 11/23/2022] Open
Abstract
In recent years, the biomimetic potential of lignified or partially lignified fruit pericarps has moved into focus. For the transfer of functional principles into biomimetic applications, a profound understanding of the structural composition of the role models is important. The aim of this study was to qualitatively analyze and visualize the functional morphology of the coconut endocarp on several hierarchical levels, and to use these findings for a more precise evaluation of the toughening mechanisms in the endocarp. Eight hierarchical levels of the ripe coconut fruit were identified using different imaging techniques, including light and scanning electron microscopy as well as micro-computer-tomography. These range from the organ level of the fruit (H0) to the molecular composition (H7) of the endocarp components. A special focus was laid on the hierarchical levels of the endocarp (H3–H6). This investigation confirmed that all hierarchical levels influence the crack development in different ways and thus contribute to the pronounced fracture toughness of the coconut endocarp. By providing relevant morphological parameters at each hierarchical level with the associated toughening mechanisms, this lays the basis for transferring those properties into biomimetic technical applications.
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Affiliation(s)
- Stefanie Schmier
- Germany and Freiburg Center for Interactive Materials and Bioinspired Technologies (FIT), Georges-Köhler-Allee 105, D-79110 Freiburg, Germany
- Plant Biomechanics Group, Botanic Garden, Faculty of Biology, University of Freiburg, Schänzlestraße 1, D-79104 Freiburg, Germany
| | - Naoe Hosoda
- National Institute for Materials Science, Namiki, Tsukuba 305-0044 1-1, Japan;
| | - Thomas Speck
- Germany and Freiburg Center for Interactive Materials and Bioinspired Technologies (FIT), Georges-Köhler-Allee 105, D-79110 Freiburg, Germany
- Plant Biomechanics Group, Botanic Garden, Faculty of Biology, University of Freiburg, Schänzlestraße 1, D-79104 Freiburg, Germany
- Germany and Cluster of Excellence livMatS @ FIT, Freiburg Center for Interactive Materials and Bioinspired Technologies, Georges-Köhler-Allee 105, D-79110 Freiburg, Germany
- Correspondence: ; Tel.: +49-761-203-2875
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22
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Impact Performance of a Plate Structure with Coconut-Inspired Microchannels. APPLIED SCIENCES-BASEL 2020. [DOI: 10.3390/app10010355] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Very few studies have been conducted in the past to reveal the underlying mechanism that causes the high-impact performance of coconuts as a natural composite material and a structure. The goal of this study is to understand the dominant microstructures of coconuts with respect to mechanical impact. In this study, we use a high-resolution X-ray computed tomography (CT) machine in scanning the microstructures and analyzing the patterns of microchannels in coconut shells. By using the established patterns, we model a novel plate structure with coconut-inspired microchannels. Numerical simulation elucidates a significant improvement in crashworthiness. The microchannel design opens a path to further developing self-healing composites and intelligent composites with sensing elements embedded in the channels.
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23
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Sonego M, Fleck C, Pessan LA. Mesocarp of Brazil nut (Bertholletia excelsa) as inspiration for new impact resistant materials. BIOINSPIRATION & BIOMIMETICS 2019; 14:056002. [PMID: 31100740 DOI: 10.1088/1748-3190/ab2298] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Aiming to produce bioinspired impact and puncture resistant materials, the mesocarp of the Brazil nut (Bertholletia excelsa) was characterized. The mesocarp composition was investigated by chemical extraction and its microstructure was analyzed by optical microscopy and microtomography (microCT). A compression test evaluated the force needed to open the mesocarp shell. Shore D hardness testing and nanoindentation measured the local mechanical properties at different length scales. Brazil nut mesocarp has a higher content of lignin (56%) than other nutshells and is mainly composed of sclereids and fibers cells arranged together and not in separated layers as usually found in nature. The mesocarp has an internal and external layer with fibers oriented from peduncle to opercular opening and a middle layer where entangled fibers are latitudinally oriented. To open a Brazil nut mesocarp, compression forces of 10 079 ± 1460 N (parallel to latitudinal section) and 14 785 ± 4050 N (perpendicular to latitudinal section) are needed. Such forces are higher than the forces needed to open most nutshells, if fracture force is normalized by shell thickness. The Shore D hardness test showed that hardness is uniform in the mesocarp, although it is higher in the center of the thickness than close to the inner or outer surface. The cell wall of fibers has a higher reduced modulus than the cell wall of sclereids although they have a similar hardness. These microstructural and mechanical results indicate that Brazil nutshell has great potential as a source for bioinspiration and motivates further studies.
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Affiliation(s)
- M Sonego
- Federal University of São Carlos (UFSCar), Graduate Program in Materials Science and Engineering (PPG-CEM), São Carlos, SP, Brazil. Author to whom correspondence should be addressed
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du Plessis A, Broeckhoven C. Looking deep into nature: A review of micro-computed tomography in biomimicry. Acta Biomater 2019; 85:27-40. [PMID: 30543937 DOI: 10.1016/j.actbio.2018.12.014] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Revised: 11/20/2018] [Accepted: 12/07/2018] [Indexed: 11/25/2022]
Abstract
Albert Einstein once said "look deep into nature, and then you will understand everything better". Looking deep into nature has in the last few years become much more achievable through the use of high-resolution X-ray micro-computed tomography (microCT). The non-destructive nature of microCT, combined with three-dimensional visualization and analysis, allows for the most complete internal and external "view" of natural materials and structures at both macro- and micro-scale. This capability brings with it the possibility to learn from nature at an unprecedented level of detail in full three dimensions, allowing us to improve our current understanding of structures, learn from them and apply them to solve engineering problems. The use of microCT in the fields of biomimicry, biomimetic engineering and bioinspiration is growing rapidly and holds great promise. MicroCT images and three-dimensional data can be used as generic bio-inspiration, or may be interpreted as detailed blueprints for specific engineering applications, i.e., reverse-engineering nature. In this review, we show how microCT has been used in bioinspiration and biomimetic studies to date, including investigations of multifunctional structures, hierarchical structures and the growing use of additive manufacturing and mechanical testing of 3D printed models in combination with microCT. The latest microCT capabilities and developments which might support biomimetic studies are described and the unique synergy between microCT and biomimicry is demonstrated. STATEMENT OF SIGNIFICANCE: This review highlights the growing use of X-ray micro computed tomography in biomimetic research. We feel the timing of this paper is excellent as there is a significant growth and interest in biomimetic research, also coupled with additive manufacturing, but still no review of the use of microCT in this field. The use of microCT for structural biomimetic and biomaterials research has huge potential but is still under-utilized, partly due to lack of knowledge of the capabilities and how it can be used in this field. We hope this review fills this gap and fuels further advances in this field using microCT.
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25
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Lauer C, Schmier S, Speck T, Nickel KG. Strength-size relationships in two porous biological materials. Acta Biomater 2018; 77:322-332. [PMID: 29981496 DOI: 10.1016/j.actbio.2018.07.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Revised: 05/24/2018] [Accepted: 07/03/2018] [Indexed: 11/29/2022]
Abstract
According to the Weibull theory for brittle materials, the mean experimental strength decreases with test specimen size. For the brittle parts of an organism this would mean that becoming larger in size results automatically in reducing strength. This unfavorable relationship was investigated for two porous, biological materials that are promising concept generators for crack deflective and energy dissipative applications in compressive overloading: the quasi-brittle coconut endocarp and the brittle spines of the sea urchin Heterocentrotus mamillatus. Segments in different volumes were prepared and tested in uniaxial compression experiments. Failure of both materials is Weibull distributed underlining that it is caused by statistically distributed flaws in the structure. However, the coconut endocarp has a much higher Weibull modulus (m = 14.1-16.5) than the spines (m = 5). The more predictable failure of the endocarp is probably attributed to a rather homogeneous microstructural design and water bound in the structure. In terms of the spines it was found that the Weibull modulus is structure dependent: More homogeneous spines feature a higher Weibull modulus than spines with a heterogeneous structure. Whereas the nearly dense endocarp exhibited, although less pronounced, the expected decrease in strength with increase in size, the spines showed a failure independently of size. This remarkable behavior may be explained with their highly porous internal structure. Small and large spines consist of struts of similar size, which constitute the porous internal structure, potentially limiting the flaw size to the size of the strut regardless of the spine size. STATEMENT OF SIGNIFICANCE Scaling is an important aspect of the biomimetic work process, since biological role models and structures have rarely the same size as their technical implementations. The algorithms of Weibull are a standard tool in material sciences to describe scaling effects in materials whose critical strength depends on statistically distributed flaws. The challenge is to apply this theory (developed for homogeneous, isotropic technical materials) to brittle and quasi-brittle biological materials with hierarchical structuring. This study is a first approach to verify whether the Weibull theory can be applied to the coconut endocarp and to sea urchin spines in order to model their size/volume/property-relations.
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Affiliation(s)
- Christoph Lauer
- University of Tübingen, Department of Geosciences, Division of Applied Mineralogy, Wilhelmstraße 56, D-72074 Tübingen, Germany.
| | - Stefanie Schmier
- University of Freiburg, Faculty of Biology, Botanic Garden, Plant Biomechanics Group, Schänzlestraße 1, D-79104 Freiburg, Germany; Freiburg Center for Interactive Materials and Bioinspired Technologies (FIT), Georges-Köhler-Allee 105, D-79110 Freiburg, Germany
| | - Thomas Speck
- University of Freiburg, Faculty of Biology, Botanic Garden, Plant Biomechanics Group, Schänzlestraße 1, D-79104 Freiburg, Germany; Freiburg Center for Interactive Materials and Bioinspired Technologies (FIT), Georges-Köhler-Allee 105, D-79110 Freiburg, Germany
| | - Klaus G Nickel
- University of Tübingen, Department of Geosciences, Division of Applied Mineralogy, Wilhelmstraße 56, D-72074 Tübingen, Germany
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