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Li M, Xiao H, Sun Y, Wang T, Shi L, Wang X. Bioinspired film-terminated ridges for enhancing friction force on lubricated soft surfaces. J Mech Behav Biomed Mater 2024; 157:106660. [PMID: 39033558 DOI: 10.1016/j.jmbbm.2024.106660] [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: 04/20/2024] [Revised: 06/29/2024] [Accepted: 07/12/2024] [Indexed: 07/23/2024]
Abstract
Enhancing friction force in lubricated, compliant contacts is of particular interest due to its wide application in various engineering and biological systems. In this study, we have developed bioinspired surfaces featuring film-terminated ridges, which exhibit a significant increase in lubricated friction force compared to flat samples. We propose that the enhanced sliding friction can be attributed to the energy dissipation at the lubricated interface caused by elastic hysteresis resulting from cyclic terminal film deformation. Furthermore, increasing inter-ridge spacing or reducing terminal film thickness are favorable design criteria for achieving high friction performance. These findings contribute to our understanding of controlling lubricated friction and provide valuable insights into surface design strategies for novel functional devices.
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Affiliation(s)
- Meng Li
- Anhui Province Key Laboratory of Special and Heavy Load Robot, Anhui University of Technology, Ma'anshan, 243032, China; School of Mechanical Engineering, Anhui University of Technology, Ma'anshan, 243032, China
| | - Han Xiao
- School of Mechanical Engineering, Anhui University of Technology, Ma'anshan, 243032, China
| | - Yongjian Sun
- School of Mechanical Engineering, Anhui University of Technology, Ma'anshan, 243032, China
| | - Tao Wang
- Anhui Province Key Laboratory of Special and Heavy Load Robot, Anhui University of Technology, Ma'anshan, 243032, China; School of Mechanical Engineering, Anhui University of Technology, Ma'anshan, 243032, China
| | - Liping Shi
- School of Mechanical Engineering, Anhui University of Technology, Ma'anshan, 243032, China; Wuhu Technology and Innovation Research Institute, AHUT, Wuhu, 241000, China.
| | - Xiaolei Wang
- College of Mechanical & Electrical Engineering, Nanjing University of Aeronautics & Astronautics, Nanjing, 210016, China.
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2
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Grote M, Gorb SN, Büscher TH. The effect of age on the attachment ability of stick insects (Phasmatodea). BEILSTEIN JOURNAL OF NANOTECHNOLOGY 2024; 15:867-883. [PMID: 39076693 PMCID: PMC11285055 DOI: 10.3762/bjnano.15.72] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/20/2024] [Accepted: 07/04/2024] [Indexed: 07/31/2024]
Abstract
Many insect species have found their way into ageing research as small and easy-to-keep model organisms. A major sign of ageing is the loss of locomotory functions due to neuronal disorders or tissue wear. Soft and pliable attachment pads on the tarsi of insects adapt to the substrate texture to maximize their real contact area and, thereby, generate attachment during locomotion. In the majority of stick insects, adhesive microstructures covering those pads support attachment. Stick insects do not molt again after reaching the imaginal stage; hence, the cuticle of their pads is subject to continuous ageing. This study aims to quantify how attachment ability changes with age in the stick insect Sungaya aeta Hennemann, 2023 and elucidate the age effects on the material and microstructure of the attachment apparatus. Attachment performance (adhesion and friction forces) on substrates with different roughnesses was compared between two different age groups, and the change of attachment performance was monitored extending over a larger time frame. Ageing effects on the morphology of the attachment pads and the autofluorescence of the cuticle were documented using light, scanning electron, and confocal laser scanning microscopy. The results show that both adhesion and friction forces decline with age. Deflation of the pads, scarring of the cuticle, and alteration of the autofluorescence, likely indicating stiffening of the cuticle, were observed to accumulate over time. This would reduce the attachment ability of the insect, as pads lose their pliant properties and cannot properly maintain sufficient contact area with the substrate.
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Affiliation(s)
- Marie Grote
- Functional Morphology and Biomechanics, Kiel University, Am Botanischen Garten 1-9, D-24118 Kiel, Germany
| | - Stanislav N Gorb
- Functional Morphology and Biomechanics, Kiel University, Am Botanischen Garten 1-9, D-24118 Kiel, Germany
| | - Thies H Büscher
- Functional Morphology and Biomechanics, Kiel University, Am Botanischen Garten 1-9, D-24118 Kiel, Germany
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3
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Thomas J, Gorb SN, Büscher TH. Comparative analysis of the ultrastructure and adhesive secretion pathways of different smooth attachment pads of the stick insect Medauroidea extradentata (Phasmatodea). BEILSTEIN JOURNAL OF NANOTECHNOLOGY 2024; 15:612-630. [PMID: 38887530 PMCID: PMC11181264 DOI: 10.3762/bjnano.15.52] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/29/2024] [Accepted: 05/08/2024] [Indexed: 06/20/2024]
Abstract
The mechanism by which insects achieve attachment and locomotion across diverse substrates has long intrigued scientists, prompting extensive research on the functional morphology of attachment pads. In stick insects, attachment and locomotion are facilitated by two distinct types of smooth cuticular attachment pads: the primary adhesion force-generating arolium and the friction force-generating euplantulae. They are both supported by an adhesive secretion delivered into the interspace between the attachment pads and the substrate. In this study, we analysed and compared internal morphology, material composition and ultrastructure, as well as the transportation pathways in both adhesive organs in the stick insect Medauroidea extradentata using scanning electron microscopy, micro-computed tomography, light microscopy, and confocal laser scanning microscopy. Our observations revealed structural differences between both attachment pads, reflecting their distinct functionality. Furthermore, our results delineate a potential pathway for adhesive secretions, originating from exocrine epidermal cells and traversing various layers before reaching the surface. Within the attachment pad, the fluid may influence the viscoelastic properties of the pad and control the attachment/detachment process. Understanding the material composition of attachment pads and the distribution process of the adhesive secretion can potentially aid in the development of more effective artificial attachment systems.
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Affiliation(s)
- Julian Thomas
- Functional Morphology and Biomechanics, Institute of Zoology, Kiel University, Am Botanischen Garten 9, 24118 Kiel, Germany
| | - Stanislav N Gorb
- Functional Morphology and Biomechanics, Institute of Zoology, Kiel University, Am Botanischen Garten 9, 24118 Kiel, Germany
| | - Thies H Büscher
- Functional Morphology and Biomechanics, Institute of Zoology, Kiel University, Am Botanischen Garten 9, 24118 Kiel, Germany
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4
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Lehmann FO, Gorb S, Moussian B. Spatio-temporal distribution and genetic background of elastic proteins inside the chitin/chitosan matrix of insects including their functional significance for locomotion. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2024; 168:104089. [PMID: 38485097 DOI: 10.1016/j.ibmb.2024.104089] [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: 11/27/2023] [Revised: 02/14/2024] [Accepted: 02/15/2024] [Indexed: 03/26/2024]
Abstract
In insects, cuticle proteins interact with chitin and chitosan of the exoskeleton forming crystalline, amorphic or composite material structures. The biochemical and mechanical composition of the structure defines the cuticle's physical properties and thus how the insect cuticle behaves under mechanical stress. The tissue-specific ratio between chitin and chitosan and its pattern of deacetylation are recognized and interpreted by cuticle proteins depending on their local position in the body. Despite previous research, the assembly of the cuticle composites in time and space including its functional impact is widely unexplored. This review is devoted to the genetics underlying the temporal and spatial distribution of elastic proteins and the potential function of elastic proteins in insects with a focus on Resilin in the fruit fly Drosophila. The potential impact and function of localized patches of elastic proteins is discussed for movements in leg joints, locomotion and damage resistance of the cuticle. We conclude that an interdisciplinary research approach serves as an integral example for the molecular mechanisms of generation and interpretation of the chitin/chitosan matrix, not only in Drosophila but also in other arthropod species, and might help to synthesize artificial material composites.
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Affiliation(s)
- Fritz-Olaf Lehmann
- Fritz-Olaf Lehmann, Department of Animal Physiology, University of Rostock, Albert-Einstein-Str. 3, 18059, Rostock, Germany.
| | - Stanislav Gorb
- Stanislav Gorb, Functional Morphology and Biomechanics, Kiel University, Am Botanischen Garten 1-9, 24118, Kiel, Germany.
| | - Bernard Moussian
- Bernard Moussian, Institute Sophia Agrobiotech, University of Nice Sophia Antipolis, 38 Av. Emile Henriot, 06000, Nice, France.
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5
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Salerno G, Rebora M, Gorb E, Gorb S. Mechanoecology: biomechanical aspects of insect-plant interactions. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2024; 210:249-265. [PMID: 38480551 PMCID: PMC10994878 DOI: 10.1007/s00359-024-01698-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2024] [Revised: 02/29/2024] [Accepted: 03/02/2024] [Indexed: 04/05/2024]
Abstract
Plants and herbivorous insects as well as their natural enemies, such as predatory and parasitoid insects, are united by intricate relationships. During the long period of co-evolution with insects, plants developed a wide diversity of features to defence against herbivores and to attract pollinators and herbivores' natural enemies. The chemical basis of insect-plant interactions is established and many examples are studied, where feeding and oviposition site selection of phytophagous insects are dependent on the plant's secondary chemistry. However, often overlooked mechanical interactions between insects and plants can be rather crucial. In the context of mechanoecology, the evolution of plant surfaces and insect adhesive pads is an interesting example of competition between insect attachment systems and plant anti-attachment surfaces. The present review is focused on mechanical insect-plant interactions of some important pest species, such as the polyphagous Southern Green Stinkbug Nezara viridula and two frugivorous pest species, the polyphagous Mediterranean fruit fly Ceratitis capitata and the monophagous olive fruit fly Bactrocera oleae. Their ability to attach to plant surfaces characterised by different features such as waxes and trichomes is discussed. Some attention is paid also to Coccinellidae, whose interaction with plant leaf surfaces is substantial across all developmental stages in both phytophagous and predatory species that feed on herbivorous insects. Finally, the role of different kinds of anti-adhesive nanomaterials is discussed. They can reduce the attachment ability of insect pests to natural and artificial surfaces, potentially representing environmental friendly alternative methods to reduce insect pest impact in agriculture.
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Affiliation(s)
- Gianandrea Salerno
- Dipartimento di Scienze Agrarie, Alimentari e Ambientali, University of Perugia, Borgo XX Giugno, Perugia, 06121, Italy
| | - Manuela Rebora
- Dipartimento di Chimica, Biologia e Biotecnologie, University of Perugia, Via Elce di Sotto 8, Perugia, 06121, Italy.
| | - Elena Gorb
- Department of Functional Morphology and Biomechanics, Zoological Institute, Kiel University, Am Botanischen Garten 9, 24098, Kiel, Germany
| | - Stanislav Gorb
- Department of Functional Morphology and Biomechanics, Zoological Institute, Kiel University, Am Botanischen Garten 9, 24098, Kiel, Germany
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6
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Thomas J, Gorb SN, Büscher TH. Influence of surface free energy of the substrate and flooded water on the attachment performance of stick insects (Phasmatodea) with different adhesive surface microstructures. J Exp Biol 2023; 226:286279. [PMID: 36606728 DOI: 10.1242/jeb.244295] [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: 03/18/2022] [Accepted: 12/28/2022] [Indexed: 01/07/2023]
Abstract
Stick and leaf insects (Phasmatodea) are exclusively herbivores. As they settle in a broad range of habitats, they need to attach to and walk on a wide variety of plant substrates, which can vary in their surface free energy (SFE). The adhesive microstructures (AMs) on the euplantulae of phasmids are assumed to be adapted to such substrate properties. Moreover, the natural substrates can often be covered with water as a result of high relative humidity or rain. Although considerable experimental research has been carried out on different aspects of stick insect attachment, the adaptations to cope with the influence of flooded water on attachment performance remain unclear. To elucidate the role of AMs in this context, we here measured attachment forces in three species of stick insects with different AMs. The results show that attachment forces of the three species studied were influenced by the SFE and the presence of water: they all showed higher pull-off (vertical) and traction (horizontal) forces on dry surfaces, compared with when the surfaces were covered with a water film. However, the extent to which the surface properties influenced attachment differed depending on the species and its AMs. All three species showed approximately the same attachment performance on dry surfaces with different surface free energy but maintained attachment underwater to different extents.
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Affiliation(s)
- Julian Thomas
- Functional Morphology and Biomechanics, Institute of Zoology, Kiel University, Am Botanischen Garten 9, 24118 Kiel, Germany
| | - Stanislav N Gorb
- Functional Morphology and Biomechanics, Institute of Zoology, Kiel University, Am Botanischen Garten 9, 24118 Kiel, Germany
| | - Thies H Büscher
- Functional Morphology and Biomechanics, Institute of Zoology, Kiel University, Am Botanischen Garten 9, 24118 Kiel, Germany
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7
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Core-shell dry adhesives for rough surfaces via electrically responsive self-growing strategy. Nat Commun 2022; 13:7659. [PMID: 36496484 PMCID: PMC9741600 DOI: 10.1038/s41467-022-35436-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Accepted: 12/02/2022] [Indexed: 12/13/2022] Open
Abstract
Bioinspired dry adhesives have an extraordinary impact in the field of robotic manipulation and locomotion. However, there is a considerable difference between artificial structures and biological ones regarding surface adaptability, especially for rough surfaces. This can be attributed to their distinct structural configuration and forming mechanism. Here, we propose a core-shell adhesive structure that is obtained through a growth strategy, i.e., an electrically responsive self-growing core-shell structure. This growth strategy results in a specific mushroom-shaped structure with a rigid core and a soft shell, which exhibits excellent adhesion on typical target surfaces with roughness ranging from the nanoscale to the microscale up to dozens of micrometers. The proposed adhesion strategy extends dry adhesives from smooth surfaces to rough ones, especially for rough surfaces with roughness up to dozens or hundreds of micrometers, opening an avenue for the development of dry adhesive-based devices and systems.
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Bergmann JB, Moatsou D, Steiner U, Wilts BD. Bio-inspired materials to control and minimise insect attachment. BIOINSPIRATION & BIOMIMETICS 2022; 17:051001. [PMID: 36099911 DOI: 10.1088/1748-3190/ac91b9] [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: 12/06/2021] [Accepted: 09/13/2022] [Indexed: 06/15/2023]
Abstract
More than three quarters of all animal species on Earth are insects, successfully inhabiting most ecosystems on the planet. Due to their opulence, insects provide the backbone of many biological processes, but also inflict adverse impacts on agricultural and stored products, buildings and human health. To countermeasure insect pests, the interactions of these animals with their surroundings have to be fully understood. This review focuses on the various forms of insect attachment, natural surfaces that have evolved to counter insect adhesion, and particularly features recently developed synthetic bio-inspired solutions. These bio-inspired solutions often enhance the variety of applicable mechanisms observed in nature and open paths for improved technological solutions that are needed in a changing global society.
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Affiliation(s)
- Johannes B Bergmann
- Adolphe Merkle Institute, University of Fribourg, Chemin des Verdiers 4, 1700 Fribourg, Switzerland
| | - Dafni Moatsou
- Institute of Organic Chemistry, Karlsruhe Institute for Technology, Fritz-Haber-Weg 6, 76131 Karlsruhe, Germany
| | - Ullrich Steiner
- Adolphe Merkle Institute, University of Fribourg, Chemin des Verdiers 4, 1700 Fribourg, Switzerland
| | - Bodo D Wilts
- Adolphe Merkle Institute, University of Fribourg, Chemin des Verdiers 4, 1700 Fribourg, Switzerland
- Chemistry and Physics of Materials, University of Salzburg, Jakob-Haringer-Str. 2a, 5020 Salzburg, Austria
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9
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Burack J, Gorb SN, Büscher TH. Attachment Performance of Stick Insects (Phasmatodea) on Plant Leaves with Different Surface Characteristics. INSECTS 2022; 13:insects13100952. [PMID: 36292904 PMCID: PMC9604322 DOI: 10.3390/insects13100952] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Revised: 10/13/2022] [Accepted: 10/16/2022] [Indexed: 05/25/2023]
Abstract
Herbivorous insects and plants exemplify a longstanding antagonistic coevolution, resulting in the development of a variety of adaptations on both sides. Some plant surfaces evolved features that negatively influence the performance of the attachment systems of insects, which adapted accordingly as a response. Stick insects (Phasmatodea) have a well-adapted attachment system with paired claws, pretarsal arolium and tarsal euplantulae. We measured the attachment ability of Medauroidea extradentata with smooth surface on the euplantulae and Sungaya inexpectata with nubby microstructures of the euplantulae on different plant substrates, and their pull-off and traction forces were determined. These species represent the two most common euplantulae microstructures, which are also the main difference between their respective attachment systems. The measurements were performed on selected plant leaves with different properties (smooth, trichome-covered, hydrophilic and covered with crystalline waxes) representing different types among the high diversity of plant surfaces. Wax-crystal-covered substrates with fine roughness revealed the lowest, whereas strongly structured substrates showed the highest attachment ability of the Phasmatodea species studied. Removal of the claws caused lower attachment due to loss of mechanical interlocking. Interestingly, the two species showed significant differences without claws on wax-crystal-covered leaves, where the individuals with nubby euplantulae revealed stronger attachment. Long-lasting effects of the leaves on the attachment ability were briefly investigated, but not confirmed.
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Abstract
Bio-inspired surfaces enabling wet adhesion management are of significant interest for applications in the field of biomedicine, as components of bionic robots and as wearable devices. In the course of biological evolution, many organisms have evolved wet adhesive surfaces with strong attachment ability. Insects enhance their adhesion on contact substrates using secreted adhesive liquids. Here we discuss concepts of bio-inspired wet adhesion. First, remaining challenges associated with the understanding and the design of biological and artificial wet adhesive systems as well as strategies to supply adhesive liquids to their contact surfaces are reviewed. Then, future directions to construct wet adhesive surfaces with liquids are discussed in detail. Finally, a model of wet adhesion management with liquids is suggested, which might help the design of next-generation bio-inspired wet adhesive surfaces.
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Affiliation(s)
- Yupeng Chen
- Key Laboratory of Bio-inspired Smart Interfacial Science and Technology of Ministry of Education, School of Chemistry, Beihang University, Beijing 100191, P.R. China
- Corresponding author
| | - Zhongpeng Zhu
- Key Laboratory of Bio-inspired Smart Interfacial Science and Technology of Ministry of Education, School of Chemistry, Beihang University, Beijing 100191, P.R. China
| | - Martin Steinhart
- Institut für Chemie neuer Materialien and CellNanOs, Universität Osnabrück, Barbarastr. 7, 49069 Osnabrück, Germany
- Corresponding author
| | - Stanislav N. Gorb
- Functional Morphology and Biomechanics, Zoological Institute, Kiel University, Am Botanischen Garten 9, 24118 Kiel, Germany
- Corresponding author
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11
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Tramsen HT, Heepe L, Gorb SN. Bioinspired Granular Media Friction Pad: A Universal System for Friction Enhancement on Variety of Substrates. Biomimetics (Basel) 2022; 7:biomimetics7010009. [PMID: 35076467 PMCID: PMC8788473 DOI: 10.3390/biomimetics7010009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Revised: 12/28/2021] [Accepted: 01/01/2022] [Indexed: 11/16/2022] Open
Abstract
The granular media friction pad (GMFP) inspired by the biological smooth attachment pads of cockroaches and grasshoppers employs passive jamming, to create high friction forces on a large variety of substrates. The granular medium inside the pad is encased by a flexible membrane which at contact formation greatly adapts to the substrate profile. Upon applying load, the granular medium undergoes the jamming transition and changes from fluid-like to solid-like properties. The jammed granular medium, in combination with the deformation of the encasing elastic membrane, results in high friction forces on a multitude of substrate topographies. Here we explore the effect of elasticity variation on the generation of friction by varying granular media filling quantity as well as membrane modulus and thickness. We systematically investigate contact area and robustness against substrate contamination, and we also determine friction coefficients for various loading forces and substrates. Depending on the substrate topography and loading forces, a low filling quantity and a thin, elastic membrane can be favorable, in order to generate the highest friction forces.
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12
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Li C, Gorb SN, Rajabi H. Biomechanical strategies to reach a compromise between stiffness and flexibility in hind femora of desert locusts. Acta Biomater 2021; 134:490-498. [PMID: 34293506 DOI: 10.1016/j.actbio.2021.07.030] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Revised: 07/11/2021] [Accepted: 07/13/2021] [Indexed: 11/28/2022]
Abstract
Insect cuticle can reach a wide range of material properties, which is thought to be the result of adaptations to applied mechanical stresses. Biomechanical mechanisms behind these property variations remain largely unknown. To fill this gap, here we performed a comprehensive study by simultaneous investigation of the microstructure, sclerotization and the elasticity modulus of the specialized cuticle of the femora of desert locusts. We hypothesized that, considering their different roles in jumping, the femora of fore-, mid- and hind legs should be equipped with cuticles that have different mechanical properties. Surprisingly, our results showed that the hind femur, which typically bears higher stresses, has a lower elasticity modulus than the fore and mid femora in the longitudinal direction. This is likely due to the lower sclerotization and different microstructure of the hind femur cuticle. This allows for some deformability in the femur wall and is likely to reduce the risk of mechanical failure. In contrast to both other femora, the hind femur is also equipped with a set of sclerotized ridges that are likely to provide it with the required stiffness to withstand the mechanical loads during walking and jumping. This paper is one of only a few comprehensive studies on insect cuticle, which advances the current understanding of the relationship between the structure, material property and function in this complex biological composite. STATEMENT OF SIGNIFICANCE: Insect cuticle is a biological composite with strong anisotropy and wide ranges of material properties. Using an example of the femoral cuticle of desert locusts, we measured the elasticity modulus, microstructure and sclerotization level of the cuticle. Our results show that, although the hind femur withstands most of the stress during locomotion, it has a lower elasticity modulus than the fore and mid femora. This is likely to be a functional adaption to jumping, in order to allow small deformations of the femur wall and reduce the risk of material failure. Our results deepen the current understanding of the structure-material-function relationship in the complex insect cuticle.
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Affiliation(s)
- Chuchu Li
- Functional Morphology and Biomechanics, Institute of Zoology, Kiel University, Kiel, Germany.
| | - Stanislav N Gorb
- Functional Morphology and Biomechanics, Institute of Zoology, Kiel University, Kiel, Germany
| | - Hamed Rajabi
- Functional Morphology and Biomechanics, Institute of Zoology, Kiel University, Kiel, Germany; Division of Mechanical Engineering and Design, School of Engineering, London South Bank University, London, UK
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13
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Büscher TH, Gorb SN. Physical constraints lead to parallel evolution of micro- and nanostructures of animal adhesive pads: a review. BEILSTEIN JOURNAL OF NANOTECHNOLOGY 2021; 12:725-743. [PMID: 34354900 PMCID: PMC8290099 DOI: 10.3762/bjnano.12.57] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Accepted: 06/30/2021] [Indexed: 05/25/2023]
Abstract
Adhesive pads are functional systems with specific micro- and nanostructures which evolved as a response to specific environmental conditions and therefore exhibit convergent traits. The functional constraints that shape systems for the attachment to a surface are general requirements. Different strategies to solve similar problems often follow similar physical principles, hence, the morphology of attachment devices is affected by physical constraints. This resulted in two main types of attachment devices in animals: hairy and smooth. They differ in morphology and ultrastructure but achieve mechanical adaptation to substrates with different roughness and maximise the actual contact area with them. Species-specific environmental surface conditions resulted in different solutions for the specific ecological surroundings of different animals. As the conditions are similar in discrete environments unrelated to the group of animals, the micro- and nanostructural adaptations of the attachment systems of different animal groups reveal similar mechanisms. Consequently, similar attachment organs evolved in a convergent manner and different attachment solutions can occur within closely related lineages. In this review, we present a summary of the literature on structural and functional principles of attachment pads with a special focus on insects, describe micro- and nanostructures, surface patterns, origin of different pads and their evolution, discuss the material properties (elasticity, viscoelasticity, adhesion, friction) and basic physical forces contributing to adhesion, show the influence of different factors, such as substrate roughness and pad stiffness, on contact forces, and review the chemical composition of pad fluids, which is an important component of an adhesive function. Attachment systems are omnipresent in animals. We show parallel evolution of attachment structures on micro- and nanoscales at different phylogenetic levels, focus on insects as the largest animal group on earth, and subsequently zoom into the attachment pads of the stick and leaf insects (Phasmatodea) to explore convergent evolution of attachment pads at even smaller scales. Since convergent events might be potentially interesting for engineers as a kind of optimal solution by nature, the biomimetic implications of the discussed results are briefly presented.
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Affiliation(s)
- Thies H Büscher
- Department of Functional Morphology and Biomechanics, Institute of Zoology, Kiel University, Am Botanischen Garten 9, 24118 Kiel, Germany
| | - Stanislav N Gorb
- Department of Functional Morphology and Biomechanics, Institute of Zoology, Kiel University, Am Botanischen Garten 9, 24118 Kiel, Germany
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14
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Abstract
AbstractThe present ultrastructural investigation using scanning and transmission electron microscopy as well as light and fluorescence microscopy describes in detail the attachment devices and tarsal gland of the bug Coreus marginatus (L.) (Hemiptera: Coreidae). In particular, the fine structure of pulvilli reveals a ventral surface rich with pore channels, consistent with fluid emission, and a folded dorsal surface, which could be useful to enhance the pulvillus contact area during attachment to the substrate. The detailed description of the tarsal gland cells, whose structure is coherent with an active secretory function, allows us to consider the tarsal gland as the plausible candidate for the adhesive fluid production. Scolopidia strictly adhering to the gland cells are also described. On the basis of the fine structure of the tarsal gland, we hypothesise a fluid emission mechanism based on changes of the hydraulic pressure inside the gland, due to the unguitractor tendon movements. This mechanism could provide the fluid release based on compression of the pad and capillary suction, as demonstrated in other insects. The data here reported can contribute to understanding of insect adhesive fluid production, emission and control of its transport.
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15
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Liu Q, Tan D, Meng F, Yang B, Shi Z, Wang X, Li Q, Nie C, Liu S, Xue L. Adhesion Enhancement of Micropillar Array by Combining the Adhesive Design from Gecko and Tree Frog. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2021; 17:e2005493. [PMID: 33369100 DOI: 10.1002/smll.202005493] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Revised: 11/13/2020] [Indexed: 06/12/2023]
Abstract
It has long been demonstrated the gecko-inspired micropillar array with T-shape tips possesses the best adhesion performance of a given material. The further enhancement of the adhesion performances of T-shape micropillars can offer redundant adhesion to compensate for the inevitable improper contacts. Here, the array of T-shape polydimethylsiloxane (PDMS) micropillars is incorporated with gradient dispersed calcium carbonate nanoparticles in the micropillar stalk, termed as T-shape gradient micropillars (TG), possessing the modulus gradient with stiff tip and soft root. The gradient modulus in TG facilitates the contact formation and regulates the stress at the detaching interface, resulting in a 4.6 times adhesion and 2.4 times friction as compared with the pure PDMS T-shape micropillar arrays. The study here provides a new design strategy for the super-strong structured dry adhesives.
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Affiliation(s)
- Quan Liu
- School of Power and Mechanical Engineering, The Institute of Technological Science, Wuhan University, South Donghu Road 8, Wuhan, 430072, China
| | - Di Tan
- School of Power and Mechanical Engineering, The Institute of Technological Science, Wuhan University, South Donghu Road 8, Wuhan, 430072, China
| | - Fandong Meng
- School of Power and Mechanical Engineering, The Institute of Technological Science, Wuhan University, South Donghu Road 8, Wuhan, 430072, China
| | - Baisong Yang
- School of Power and Mechanical Engineering, The Institute of Technological Science, Wuhan University, South Donghu Road 8, Wuhan, 430072, China
| | - Zhekun Shi
- School of Power and Mechanical Engineering, The Institute of Technological Science, Wuhan University, South Donghu Road 8, Wuhan, 430072, China
| | - Xin Wang
- School of Power and Mechanical Engineering, The Institute of Technological Science, Wuhan University, South Donghu Road 8, Wuhan, 430072, China
| | - Qian Li
- School of Power and Mechanical Engineering, The Institute of Technological Science, Wuhan University, South Donghu Road 8, Wuhan, 430072, China
| | - Chang Nie
- School of Power and Mechanical Engineering, The Institute of Technological Science, Wuhan University, South Donghu Road 8, Wuhan, 430072, China
| | - Sheng Liu
- School of Power and Mechanical Engineering, The Institute of Technological Science, Wuhan University, South Donghu Road 8, Wuhan, 430072, China
| | - Longjian Xue
- School of Power and Mechanical Engineering, The Institute of Technological Science, Wuhan University, South Donghu Road 8, Wuhan, 430072, China
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16
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Lerch S, Zuber R, Gehring N, Wang Y, Eckel B, Klass KD, Lehmann FO, Moussian B. Resilin matrix distribution, variability and function in Drosophila. BMC Biol 2020; 18:195. [PMID: 33317537 PMCID: PMC7737337 DOI: 10.1186/s12915-020-00902-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2020] [Accepted: 10/19/2020] [Indexed: 11/23/2022] Open
Abstract
Background Elasticity prevents fatigue of tissues that are extensively and repeatedly deformed. Resilin is a resilient and elastic extracellular protein matrix in joints and hinges of insects. For its mechanical properties, Resilin is extensively analysed and applied in biomaterial and biomedical sciences. However, there is only indirect evidence for Resilin distribution and function in an insect. Commonly, the presence of dityrosines that covalently link Resilin protein monomers (Pro-Resilin), which are responsible for its mechanical properties and fluoresce upon UV excitation, has been considered to reflect Resilin incidence. Results Using a GFP-tagged Resilin version, we directly identify Resilin in pliable regions of the Drosophila body, some of which were not described before. Interestingly, the amounts of dityrosines are not proportional to the amounts of Resilin in different areas of the fly body, arguing that the mechanical properties of Resilin matrices vary according to their need. For a functional analysis of Resilin matrices, applying the RNA interference and Crispr/Cas9 techniques, we generated flies with reduced or eliminated Resilin function, respectively. We find that these flies are flightless but capable of locomotion and viable suggesting that other proteins may partially compensate for Resilin function. Indeed, localizations of the potentially elastic protein Cpr56F and Resilin occasionally coincide. Conclusions Thus, Resilin-matrices are composite in the way that varying amounts of different elastic proteins and dityrosinylation define material properties. Understanding the biology of Resilin will have an impact on Resilin-based biomaterial and biomedical sciences.
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Affiliation(s)
- Steven Lerch
- Applied Zoology, Technical University of Dresden, Dresden, Germany.,Animal Genetics, Interfaculty Institute of Cell Biology, University of Tübingen, Tübingen, Germany.,Senckenberg Natural History Collections, Dresden, Germany
| | - Renata Zuber
- Applied Zoology, Technical University of Dresden, Dresden, Germany
| | - Nicole Gehring
- Animal Genetics, Interfaculty Institute of Cell Biology, University of Tübingen, Tübingen, Germany
| | - Yiwen Wang
- Animal Genetics, Interfaculty Institute of Cell Biology, University of Tübingen, Tübingen, Germany
| | - Barbara Eckel
- Applied Zoology, Technical University of Dresden, Dresden, Germany
| | | | | | - Bernard Moussian
- Applied Zoology, Technical University of Dresden, Dresden, Germany. .,Animal Genetics, Interfaculty Institute of Cell Biology, University of Tübingen, Tübingen, Germany. .,CNRS, Inserm Institute of Biology Valrose, Université Côte d'Azur, Nice, France.
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17
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Flenner S, Schaber CF, Krasnov I, Stieglitz H, Rosenthal M, Burghammer M, Gorb SN, Müller M. Multiple Mechanical Gradients are Responsible for the Strong Adhesion of Spider Attachment Hair. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2020; 32:e2002758. [PMID: 32743886 DOI: 10.1002/adma.202002758] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Revised: 07/03/2020] [Indexed: 05/16/2023]
Abstract
Wandering spiders climb vertically and walk upside-down on rough and smooth surfaces using a nanostructured attachment system on their feet. The spiders are assumed to adhere by intermolecular van der Waals forces between the adhesive structures and the substrate. The adhesive elements are arranged highly ordered on the hierarchically structured attachment hair (setae). While walking, it has been suggested that the spiders apply a shear force on their legs to increase friction. However, the detailed mechanical behavior of the hair's structures during attachment and detachment remains unknown. Here, gradients of the mechanical properties of the attachment hair on different length scales that have evolved to support attachment, stabilize adhesion in contact, and withstand high stress at detachment, examined by in situ experiments, are shown. Shearing helps to self-align the adhesive elements with the substrate. The study is anticipated to contribute to the development of optimized artificial dry adhesives.
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Affiliation(s)
- Silja Flenner
- Helmholtz-Zentrum Geesthacht, Max-Planck-Str. 1, Geesthacht, 21502, Germany
- Institute of Experimental and Applied Physics, Kiel University, Kiel, 24098, Germany
| | - Clemens F Schaber
- Functional Morphology and Biomechanics, Zoological Institute, Kiel University, Kiel, 24098, Germany
| | - Igor Krasnov
- Institute of Experimental and Applied Physics, Kiel University, Kiel, 24098, Germany
| | - Hergen Stieglitz
- Helmholtz-Zentrum Geesthacht, Max-Planck-Str. 1, Geesthacht, 21502, Germany
- Institute of Experimental and Applied Physics, Kiel University, Kiel, 24098, Germany
| | - Martin Rosenthal
- European Synchrotron Radiation Facility (ESRF), 71, avenue des Martyrs, CS 40220, Grenoble Cedex 9, 38043, France
| | - Manfred Burghammer
- European Synchrotron Radiation Facility (ESRF), 71, avenue des Martyrs, CS 40220, Grenoble Cedex 9, 38043, France
| | - Stanislav N Gorb
- Functional Morphology and Biomechanics, Zoological Institute, Kiel University, Kiel, 24098, Germany
| | - Martin Müller
- Helmholtz-Zentrum Geesthacht, Max-Planck-Str. 1, Geesthacht, 21502, Germany
- Institute of Experimental and Applied Physics, Kiel University, Kiel, 24098, Germany
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18
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Jafarpour M, Eshghi S, Darvizeh A, Gorb S, Rajabi H. Functional significance of graded properties of insect cuticle supported by an evolutionary analysis. J R Soc Interface 2020; 17:20200378. [PMID: 32674704 DOI: 10.1098/rsif.2020.0378] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The exoskeleton of nearly all insects consists of a flexible core and a stiff shell. The transition between these two is often characterized by a gradual change in the stiffness. However, the functional significance of this stiffness gradient is unknown. Here by combining finite-element analysis and multi-objective optimization, we simulated the mechanical response of about 3000 unique gradients of the elastic modulus to normal contacts. We showed that materials with exponential gradients of the elastic modulus could achieve an optimal balance between the load-bearing capacity and resilience. This is very similar to the elastic modulus gradient observed in insect cuticle and, therefore, suggests cuticle adaptations to applied mechanical stresses; this is likely to facilitate the function of insect cuticle as a protective barrier. Our results further indicate that the relative thickness of compositionally different regions in insect cuticle is similar to the optimal estimation. We expect our findings to inform the design of engineered materials with improved mechanical performance.
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Affiliation(s)
- M Jafarpour
- Institute of Zoology, Functional Morphology and Biomechanics, Kiel University, Kiel, Germany.,Faculty of Mechanical Engineering, University of Guilan, Rasht, Iran
| | - Sh Eshghi
- Institute of Zoology, Functional Morphology and Biomechanics, Kiel University, Kiel, Germany
| | - A Darvizeh
- Faculty of Mechanical Engineering, University of Guilan, Rasht, Iran
| | - S Gorb
- Institute of Zoology, Functional Morphology and Biomechanics, Kiel University, Kiel, Germany
| | - H Rajabi
- Institute of Zoology, Functional Morphology and Biomechanics, Kiel University, Kiel, Germany
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19
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Mo X, Romano D, Miraglia M, Ge W, Stefanini C. Effect of Substrates' Compliance on the Jumping Mechanism of Locusta migratoria. Front Bioeng Biotechnol 2020; 8:661. [PMID: 32775320 PMCID: PMC7381386 DOI: 10.3389/fbioe.2020.00661] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2020] [Accepted: 05/28/2020] [Indexed: 11/13/2022] Open
Abstract
Locusts generally live and move in complex environments including different kind of substrates, ranging from compliant leaves to stiff branches. Since the contact force generates deformation of the substrate, a certain amount of energy is dissipated each time when locust jumps from a compliant substrate. In published researches, it is proven that only tree frogs are capable of recovering part of the energy that had been accumulated in the substrate as deformation energy in the initial pushing phase, just before leaving the ground. The jumping performances of adult Locusta migratoria on substrates of three different compliances demonstrate that locusts are able to adapt their jumping mode to the mechanical characteristics of the substrate. Recorded high speed videos illustrate the existence of deformed substrate's recoil before the end of the takeoff phase when locusts jump from compliant substrates, which indicates their ability of recovering part of energy from the substrate deformation. This adaptability is supposed to be related to the catapult mechanism adopted in locusts' jump thanks to their long hind legs and sticky tarsus. These findings improve the understanding of the jumping mechanism of locusts, as well as can be used to develop artifact outperforming current jumping robots in unstructured scenarios.
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Affiliation(s)
- Xiaojuan Mo
- School of Mechanical Engineering, Northwestern Polytechnical University, Xi'an, China
| | - Donato Romano
- Sant'Anna School of Advanced Studies, The BioRobotics Institute, Pisa, Italy
- Department of Excellence in Robotics & A.I., Sant'Anna School of Advanced Studies, Pisa, Italy
| | - Marco Miraglia
- Sant'Anna School of Advanced Studies, The BioRobotics Institute, Pisa, Italy
| | - Wenjie Ge
- School of Mechanical Engineering, Northwestern Polytechnical University, Xi'an, China
| | - Cesare Stefanini
- Sant'Anna School of Advanced Studies, The BioRobotics Institute, Pisa, Italy
- Department of Excellence in Robotics & A.I., Sant'Anna School of Advanced Studies, Pisa, Italy
- Healthcare Engineering Innovation Center (HEIC), Khalifa University, Abu Dhabi, United Arab Emirates
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20
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Li C, Gorb SN, Rajabi H. Cuticle sclerotization determines the difference between the elastic moduli of locust tibiae. Acta Biomater 2020; 103:189-195. [PMID: 31843719 DOI: 10.1016/j.actbio.2019.12.013] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Revised: 12/09/2019] [Accepted: 12/10/2019] [Indexed: 11/29/2022]
Abstract
A striking characteristic of insect cuticle is the wide range of its material property values, with respect to stiffness, strength and toughness. The elastic modulus of cuticle, for instance, ranges over seven orders of magnitude in different structures and different species. Previous studies suggested that this characteristic is influenced by the microstructure and sclerotization of cuticle. However, the relative role of the two factors in determining the material properties of cuticle is unknown. Here we used a combination of scanning electron microscopy (SEM), confocal laser scanning microscopy (CLSM) and nanoindentation, to investigate the effect of microstructure and sclerotization on the elastic modulus of tibiae of desert locusts. Our results showed that tibial cuticle is an anisotropic material with the highest elastic modulus along the tibial axis. This is likely because majority of the fibers in the cuticle are oriented along this axis. We also found that the hind tibia has a significantly higher elastic modulus, compared with the fore and mid tibiae. This is likely due to the higher sclerotization level of the hind tibia cuticle, and seems to be an adaptation to the locust locomotion by jumping, in which axial loads in the hind tibiae may reach several times the insect body weight. Our results suggest that while sclerotization determines the difference between the elastic moduli of the tibiae, anisotropic properties of each tibia is controlled by the specific fiber orientation. Our study provides one of only a few comprehensive investigations on insect cuticle, and helps to better understand the structure-material-function relationship in this complex biological composite. STATEMENT OF SIGNIFICANCE: Insect cuticle is a biological composite with strong anisotropy and wide ranges of material properties. Using an example of the tibial cuticle of desert locusts, we examined the role of two influential factors on the elastic modulus of cuticle: microstructure and sclerotization. Our results suggested the strong influence of sclerotization on the variation of the elastic modulus among fore, mid and hind tibiae, and that of the microstructure on the anisotropy of each tibia. Our results deepens the current understanding of the structure-material-function relationship in complex insect cuticle.
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Affiliation(s)
- Chuchu Li
- Functional Morphology and Biomechanics, Institute of Zoology, Kiel University, Kiel, Germany.
| | - Stanislav N Gorb
- Functional Morphology and Biomechanics, Institute of Zoology, Kiel University, Kiel, Germany
| | - Hamed Rajabi
- Functional Morphology and Biomechanics, Institute of Zoology, Kiel University, Kiel, Germany
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21
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Salerno G, Rebora M, Piersanti S, Gorb E, Gorb S. Mechanical ecology of fruit-insect interaction in the adult Mediterranean fruit fly Ceratitis capitata (Diptera: Tephritidae). ZOOLOGY 2020; 139:125748. [PMID: 32078916 DOI: 10.1016/j.zool.2020.125748] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Revised: 01/14/2020] [Accepted: 01/16/2020] [Indexed: 12/21/2022]
Abstract
Fruit features represent a trade-off between dispersal and protection against frugivore insects. To prevent insect attack, plants evolved chemical and physical barriers, mainly studied in leaves, while limited knowledge is available for fruits, especially concerning mechanical barriers. We used the Mediterranean fruit fly to shed light on the mechanical ecology of insect-fruit attachment in a pest species. We tested the following hypotheses: is there any sexual dimorphism in attachment devices and attachment ability? Can the attachment ability of females of Ceratitis capitata to fruits of various host plants vary according to fruit surfaces with different morphology (smooth, hairy, waxy) or physico-chemical properties? The tarsal attachment devices were studied using Cryo-SEM and TEM. The maximum friction forces of C. capitata females on fruit surfaces of typical host plants were evaluated using a load cell force transducer. The attachment ability of both sexes on artificial surfaces was evaluated using a centrifugal force tester. Our data revealed sexual dimorphism in the size of pulvilli, which are wider in females. A higher friction force is exerted by females in comparison with males, in agreement with the need to firmly adhere to the host plant fruit during oviposition. Among the tested fruits, the stronger friction force was recorded on hairy or rough surfaces while a force reduction was recorded on waxy fruits. To unravel the mechanical ecology of insect-plant interaction between plants and species of Tephritidae can be useful to develop non-chemical methods to control these important crop pests.
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Affiliation(s)
- Gianandrea Salerno
- Dipartimento di Scienze Agrarie, Alimentari e Ambientali, University of Perugia, Borgo XX Giugno 74, Perugia, 06121, Italy
| | - Manuela Rebora
- Dipartimento di Chimica, Biologia e Biotecnologie, University of Perugia, Via Elce di Sotto 8, 06121, Perugia, Italy.
| | - Silvana Piersanti
- Dipartimento di Chimica, Biologia e Biotecnologie, University of Perugia, Via Elce di Sotto 8, 06121, Perugia, Italy
| | - Elena Gorb
- Department of Functional Morphology and Biomechanics, Zoological Institute, Kiel University, Am Botanischen Garten 9, 24098, Kiel, Germany
| | - Stanislav Gorb
- Department of Functional Morphology and Biomechanics, Zoological Institute, Kiel University, Am Botanischen Garten 9, 24098, Kiel, Germany
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22
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Perepelkin NV, Borodich FM, Kovalev AE, Gorb SN. Depth-Sensing Indentation as a Micro- and Nanomechanical Approach to Characterisation of Mechanical Properties of Soft, Biological, and Biomimetic Materials. NANOMATERIALS (BASEL, SWITZERLAND) 2019; 10:E15. [PMID: 31861558 PMCID: PMC7023166 DOI: 10.3390/nano10010015] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Revised: 12/13/2019] [Accepted: 12/14/2019] [Indexed: 11/16/2022]
Abstract
Classical methods of material testing become extremely complicated or impossible at micro-/nanoscale. At the same time, depth-sensing indentation (DSI) can be applied without much change at various length scales. However, interpretation of the DSI data needs to be done carefully, as length-scale dependent effects, such as adhesion, should be taken into account. This review paper is focused on different DSI approaches and factors that can lead to erroneous results, if conventional DSI methods are used for micro-/nanomechanical testing, or testing soft materials. We also review our recent advances in the development of a method that intrinsically takes adhesion effects in DSI into account: the Borodich-Galanov (BG) method, and its extended variant (eBG). The BG/eBG methods can be considered a framework made of the experimental part (DSI by means of spherical indenters), and the data processing part (data fitting based on the mathematical model of the experiment), with such distinctive features as intrinsic model-based account of adhesion, the ability to simultaneously estimate elastic and adhesive properties of materials, and non-destructive nature.
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Affiliation(s)
| | - Feodor M. Borodich
- School of Engineering, Cardiff University, Cardiff CF24 3AA, UK
- College of Aerospace Engineering, Chongqing University, Chongqing 400044, China
| | - Alexander E. Kovalev
- Department of Functional Morphology and Biomechanics, Zoological Institute of the University of Kiel, Kiel 24118, Germany
| | - Stanislav N. Gorb
- Department of Functional Morphology and Biomechanics, Zoological Institute of the University of Kiel, Kiel 24118, Germany
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23
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Büscher TH, Gorb SN. Complementary effect of attachment devices in stick insects (Phasmatodea). ACTA ACUST UNITED AC 2019; 222:jeb.209833. [PMID: 31727762 DOI: 10.1242/jeb.209833] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Accepted: 11/06/2019] [Indexed: 11/20/2022]
Abstract
Stick insects are well adapted in their locomotion to various surfaces and topographies of natural substrates. Single pad measurements characterised the pretarsal arolia of these insects as shear-sensitive adhesive pads and the tarsal euplantulae as load-sensitive friction pads. Different attachment microstructures on the euplantulae reveal an adaptation of smooth euplantulae to smooth surfaces and nubby eupantulae to a broader range of surface roughness. However, how different attachment pads and claws work in concert and how strong the contribution of different structures is to the overall attachment performance remains unclear. We therefore assessed combinatory effects in the attachment system of two stick insect species with different types of euplantular microstructures by analysing their usage in various posture situations and the performance on different levels of substrate roughness. For comparison, we provide attachment force data of the whole attachment system. The combination of claws, arolia and euplantulae provides mechanical interlocking on rough surfaces, adhesion and friction on smooth surfaces in different directions, and facilitates attachment on different inclines and on a broad range of surface roughness, with the least performance in the range 0.3-1.0 µm. On smooth surfaces, stick insects use arolia always, but employ euplantulae if the body weight can generate load on them (upright, wall). On structured surfaces, claws enable mechanical interlocking at roughnesses higher than 12 µm. On less-structured surfaces, the attachment strength depends on the use of pads and, corroborating earlier studies, favours smooth pads on smooth surfaces, but nubby euplantulae on micro-rough surfaces.
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Affiliation(s)
- Thies H Büscher
- Department of Functional Morphology and Biomechanics, Institute of Zoology, Kiel University, Am Botanischen Garten 9, 24118 Kiel, Germany
| | - Stanislav N Gorb
- Department of Functional Morphology and Biomechanics, Institute of Zoology, Kiel University, Am Botanischen Garten 9, 24118 Kiel, Germany
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24
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Aldred N. Transdisciplinary approaches to the study of adhesion and adhesives in biological systems. Philos Trans R Soc Lond B Biol Sci 2019; 374:20190191. [PMID: 31495317 DOI: 10.1098/rstb.2019.0191] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Affiliation(s)
- Nick Aldred
- School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne NE1 7RU, UK
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25
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Chen S, Deng SW, Shih C, Zhang WW, Zhang P, Ren D, Zhu YN, Gao TP. The earliest Timematids in Burmese amber reveal diverse tarsal pads of stick insects in the mid-Cretaceous. INSECT SCIENCE 2019; 26:945-957. [PMID: 29700985 DOI: 10.1111/1744-7917.12601] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2018] [Revised: 04/05/2018] [Accepted: 04/09/2018] [Indexed: 06/08/2023]
Abstract
Many extant insects have developed pad structures, euplantulae or arolia on their tarsi to increase friction or enhance adhesion for better mobility. Many polyneopteran insects with euplantulae, for example, Grylloblattodea, Mantophasmatodea and Orthoptera, have been described from the Mesozoic. However, the origin and evolution of stick insects' euplantulae are poorly understood due to rare fossil records. Here, we report the earliest fossil records of Timematodea hitherto, Tumefactipes prolongates gen. et sp. nov. and Granosicorpes lirates gen. et sp. nov., based on three specimens from mid-Cretaceous Burmese amber. Specimens of Tumefactipes prolongates gen. et sp. nov. have extremely specialized and expanded euplantulae on their tarsomere II. These new findings are the first known and the earliest fossil records about euplantula structure within Phasmatodea, demonstrating the diversity of euplantulae in Polyneoptera during the Mesozoic. Such tarsal pads might have increased friction and helped these mid-Cretaceous stick insects to climb more firmly on various surfaces, such as broad leaves, wetted tree branches or ground. These specimens provide more morphological data for us to understand the relationships of Timematodea, Euphasmatodea, Orthoptera and Embioptera, suggesting that Timematodea might be monophyletic with Euphasmatodea rather than Embioptera and Phasmatodea should have a closer relationship with Orthoptera rather than Embioptera.
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Affiliation(s)
- Sha Chen
- College of Life Sciences, Capital Normal University, Beijing, China
| | - Shi-Wo Deng
- School of Mathematical Sciences, Capital Normal University, Beijing, China
| | - Chungkun Shih
- College of Life Sciences, Capital Normal University, Beijing, China
- Department of Paleobiology, National Museum of Natural History, Smithsonian Institution, Washington, DC, USA
| | | | - Peng Zhang
- School of Mathematical Sciences, Capital Normal University, Beijing, China
| | - Dong Ren
- College of Life Sciences, Capital Normal University, Beijing, China
| | - Yi-Ning Zhu
- School of Mathematical Sciences, Capital Normal University, Beijing, China
| | - Tai-Ping Gao
- College of Life Sciences, Capital Normal University, Beijing, China
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26
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Büscher TH, Kryuchkov M, Katanaev VL, Gorb SN. Versatility of Turing patterns potentiates rapid evolution in tarsal attachment microstructures of stick and leaf insects (Phasmatodea). J R Soc Interface 2019; 15:rsif.2018.0281. [PMID: 29925583 DOI: 10.1098/rsif.2018.0281] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Accepted: 05/30/2018] [Indexed: 11/12/2022] Open
Abstract
In its evolution, the diverse group of stick and leaf insects (Phasmatodea) has undergone a rapid radiation. These insects evolved specialized structures to adhere to different surfaces typical for their specific ecological environments. The cuticle of their tarsal attachment pads (euplantulae) is known to possess a high diversity of attachment microstructures (AMS) which are suggested to reflect ecological specializations of different groups within phasmids. However, the origin of these microstructures and their developmental background remain largely unknown. Here, based on the detailed scanning electron microscopy study of pad surfaces, we present a theoretical approach to mathematically model an outstanding diversity of phasmid AMS using the reaction-diffusion model by Alan Turing. In general, this model explains pattern formation in nature. For the first time, we were able to identify eight principal patterns and simulate the transitions among these. In addition, intermediate transitional patterns were predicted by the model. The ease of transformation suggests a high adaptability of the microstructures that might explain the rapid evolution of pad characters. We additionally discuss the functional morphology of the different microstructures and their assumed advantages in the context of the ecological background of species.
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Affiliation(s)
- Thies H Büscher
- Department of Functional Morphology and Biomechanics, Zoological Institute, Kiel University, Kiel, Germany
| | - Mikhail Kryuchkov
- Department of Pharmacology and Toxicology, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
| | - Vladimir L Katanaev
- Department of Pharmacology and Toxicology, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland.,School of Biomedicine, Far Eastern Federal University, Vladivostok, Russia
| | - Stanislav N Gorb
- Department of Functional Morphology and Biomechanics, Zoological Institute, Kiel University, Kiel, Germany
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27
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Gorb SN, Pullwitt T, Kleinteich T, Busshardt P. The insect unguitractor plate in action: Force transmission and the micro CT visualizations of inner structures. JOURNAL OF INSECT PHYSIOLOGY 2019; 117:103908. [PMID: 31265818 DOI: 10.1016/j.jinsphys.2019.103908] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2018] [Revised: 06/26/2019] [Accepted: 06/28/2019] [Indexed: 06/09/2023]
Abstract
The unguitractor plate (UT) within insect tarsus was previously assumed to hold claws in a bent position with reduced muscular efforts due to the specific interlocking mechanism. In this study, the functional morphology of the unguitractor plate in the beetle Pachnoda marginata (Coleoptera, Scarabaeidae) was examined using force measurements and the micro CT visualization of the UT position at different straining states of the retractor unguis muscle tendon. Pulling forces were applied in a controlled manner to the tendon and forces elicited by the claws to the stiff substrate were simultaneously recorded, in order to understand the force transmission mechanism between the tendon and claws through the UT. After claw bending and entanglement with the substrate, the claws were not released, until the tendon was relaxed to an average of 22% of the original applied force. The time delay in the returning of the claws to their original position was observed due to the frictional mechanism between the UT and corresponding microstructures of the pretarsus. This mechanism provides energy saving, when claws are engaged with the substrate. However, physical contact between the UT and the inner pretarsal wall was not observed in preparations of prestrained tendons in the micro CT, presumably due to the deformations caused by fixation and drying procedures.
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Affiliation(s)
- Stanislav N Gorb
- Functional Morphology and Biomechanics, Zoological Institute, Kiel University, Am Botanischen Garten 1-9, D-24118 Kiel, Germany.
| | - Tom Pullwitt
- Functional Morphology and Biomechanics, Zoological Institute, Kiel University, Am Botanischen Garten 1-9, D-24118 Kiel, Germany
| | - Thomas Kleinteich
- Functional Morphology and Biomechanics, Zoological Institute, Kiel University, Am Botanischen Garten 1-9, D-24118 Kiel, Germany
| | - Philipp Busshardt
- Functional Morphology and Biomechanics, Zoological Institute, Kiel University, Am Botanischen Garten 1-9, D-24118 Kiel, Germany
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Schaber CF, Flenner S, Glisovic A, Krasnov I, Rosenthal M, Stieglitz H, Krywka C, Burghammer M, Müller M, Gorb SN. Hierarchical architecture of spider attachment setae reconstructed from scanning nanofocus X-ray diffraction data. J R Soc Interface 2019; 16:20180692. [PMID: 30958170 PMCID: PMC6364634 DOI: 10.1098/rsif.2018.0692] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2018] [Accepted: 01/08/2019] [Indexed: 11/12/2022] Open
Abstract
When sitting and walking, the feet of wandering spiders reversibly attach to many surfaces without the use of gluey secretions. Responsible for the spiders' dry adhesion are the hairy attachment pads that are built of specially shaped cuticular hairs (setae) equipped with approximately 1 µm wide and 20 nm thick plate-like contact elements (spatulae) facing the substrate. Using synchrotron-based scanning nanofocus X-ray diffraction methods, combining wide-angle X-ray diffraction/scattering and small-angle X-ray scattering, allowed substantial quantitative information to be gained about the structure and materials of these fibrous adhesive structures with 200 nm resolution. The fibre diffraction patterns showed the crystalline chitin chains oriented along the long axis of the attachment setae and increased intensity of the chitin signal dorsally within the seta shaft. The small-angle scattering signals clearly indicated an angular shift by approximately 80° of the microtrich structures that branch off the bulk hair shaft and end as the adhesive contact elements in the tip region of the seta. The results reveal the specific structural arrangement and distribution of the chitin fibres within the attachment hair's cuticle preventing material failure by tensile reinforcement and proper distribution of stresses that arise upon attachment and detachment.
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Affiliation(s)
- Clemens F. Schaber
- Functional Morphology and Biomechanics, Zoological Institute, Kiel University, 24098 Kiel, Germany
| | - Silja Flenner
- Helmholtz-Zentrum Geesthacht, Postfach 1160, 21494 Geesthacht, Germany
- Institute of Experimental and Applied Physics, Kiel University, 24098 Kiel, Germany
| | - Anja Glisovic
- Institute of Experimental and Applied Physics, Kiel University, 24098 Kiel, Germany
| | - Igor Krasnov
- Institute of Experimental and Applied Physics, Kiel University, 24098 Kiel, Germany
| | - Martin Rosenthal
- European Synchrotron Radiation Facility (ESRF), CS 40220, 38043 Grenoble Cedex 9, France
| | - Hergen Stieglitz
- Helmholtz-Zentrum Geesthacht, Postfach 1160, 21494 Geesthacht, Germany
- Institute of Experimental and Applied Physics, Kiel University, 24098 Kiel, Germany
| | - Christina Krywka
- Helmholtz-Zentrum Geesthacht, Postfach 1160, 21494 Geesthacht, Germany
| | - Manfred Burghammer
- European Synchrotron Radiation Facility (ESRF), CS 40220, 38043 Grenoble Cedex 9, France
| | - Martin Müller
- Helmholtz-Zentrum Geesthacht, Postfach 1160, 21494 Geesthacht, Germany
- Institute of Experimental and Applied Physics, Kiel University, 24098 Kiel, Germany
| | - Stanislav N. Gorb
- Functional Morphology and Biomechanics, Zoological Institute, Kiel University, 24098 Kiel, Germany
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Schaber CF, Kreitschitz A, Gorb SN. Friction-Active Surfaces Based on Free-Standing Anchored Cellulose Nanofibrils. ACS APPLIED MATERIALS & INTERFACES 2018; 10:37566-37574. [PMID: 30229647 DOI: 10.1021/acsami.8b05972] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
A specific feature of fibrous surfaces is the dependence of their mechanical properties on the alignment of the fibers. Vertically aligned fibers enhance friction and adhesion, whereas horizontal fibers are known to act as a lubricant reducing the friction. Many plants form a specific fibrous mucilage cover around their seeds upon hydration. This mucilage consists of cellulose, hemicelluloses, and strongly hydrophilic pectins. We show that the controlled critical-point drying of hydrated seed mucilage of three exemplary seed mucilage-rich plant species results in the exposure of free-standing cellulose nanofibers with a very high aspect ratio and anchored to the seed surface. The structural dimensions of the cellulose nanofibers are similar to the vertically aligned carbon nanotubes and the contact elements in the adhesion system of the gecko that show an outstanding high dry friction and adhesion. Tribological experiments demonstrate very high average friction coefficients when sliding a smooth and stiff probe over the surface of such arrays of dry free-standing cellulose nanofibrils in the range from 1.4 to 1.8. The high friction values most likely arise from bending of the single cellulose fibers and their alignment with the counterpart surface in close contact. We suggest the potential of free-standing cellulose nanofibrils of plant seed mucilage as a natural and ecologically friendly material where high contact forces to surfaces in dry environments are desired.
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Affiliation(s)
- Clemens F Schaber
- Functional Morphology and Biomechanics, Zoological Institute , Kiel University , Am Botanischen Garten 9 , 24118 Kiel , Germany
| | - Agnieszka Kreitschitz
- Functional Morphology and Biomechanics, Zoological Institute , Kiel University , Am Botanischen Garten 9 , 24118 Kiel , Germany
- Department of Plant Developmental Biology, Institute of Experimental Biology , University of Wrocław , ul. Kanonia , 50-328 Wroclaw , Poland
| | - Stanislav N Gorb
- Functional Morphology and Biomechanics, Zoological Institute , Kiel University , Am Botanischen Garten 9 , 24118 Kiel , Germany
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Woodward MA, Sitti M. Morphological intelligence counters foot slipping in the desert locust and dynamic robots. Proc Natl Acad Sci U S A 2018; 115:E8358-E8367. [PMID: 30135101 PMCID: PMC6130395 DOI: 10.1073/pnas.1804239115] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
During dynamic terrestrial locomotion, animals use complex multifunctional feet to extract friction from the environment. However, whether roboticists assume sufficient surface friction for locomotion or actively compensate for slipping, they use relatively simple point-contact feet. We seek to understand and extract the morphological adaptations of animal feet that contribute to enhancing friction on diverse surfaces, such as the desert locust (Schistocerca gregaria) [Bennet-Clark HC (1975) J Exp Biol 63:53-83], which has both wet adhesive pads and spines. A buckling region in their knee to accommodate slipping [Bayley TG, Sutton GP, Burrows M (2012) J Exp Biol 215:1151-1161], slow nerve conduction velocity (0.5-3 m/s) [Pearson KG, Stein RB, Malhotra SK (1970) J Exp Biol 53:299-316], and an ecological pressure to enhance jumping performance for survival [Hawlena D, Kress H, Dufresne ER, Schmitz OJ (2011) Funct Ecol 25:279-288] further suggest that the locust operates near the limits of its surface friction, but without sufficient time to actively control its feet. Therefore, all surface adaptation must be through passive mechanics (morphological intelligence), which are unknown. Here, we report the slipping behavior, dynamic attachment, passive mechanics, and interplay between the spines and adhesive pads, studied through both biological and robotic experiments, which contribute to the locust's ability to jump robustly from diverse surfaces. We found slipping to be surface-dependent and common (e.g., wood 1.32 ± 1.19 slips per jump), yet the morphological intelligence of the feet produces a significant chance to reengage the surface (e.g., wood 1.10 ± 1.13 reengagements per jump). Additionally, a discovered noncontact-type jump, further studied robotically, broadens the applicability of the morphological adaptations to both static and dynamic attachment.
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Affiliation(s)
- Matthew A Woodward
- Physical Intelligence Department, Max Planck Institute for Intelligent Systems, 70569 Stuttgart, Germany
| | - Metin Sitti
- Physical Intelligence Department, Max Planck Institute for Intelligent Systems, 70569 Stuttgart, Germany
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Jandausch K, Beutel RG, Pohl H, Gorb SN, Büsse S. The legs of "spider associated" parasitic primary larvae of Mantispa aphavexelte (Mantispidae, Neuroptera) - Attachment devices and phylogenetic implications. ARTHROPOD STRUCTURE & DEVELOPMENT 2018; 47:449-456. [PMID: 29902506 DOI: 10.1016/j.asd.2018.06.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2018] [Revised: 06/08/2018] [Accepted: 06/08/2018] [Indexed: 06/08/2023]
Abstract
The legs of the primary larva of Mantispa aphavexelte, parasite in egg sacks of spiders, were examined using scanning electron microscopy (SEM), histology and confocal laser scanning microscopy (CLSM). The leg morphology is described in detail, including intrinsic muscles. Functional adaptations of the leg attachment devices are discussed, especially regarding the material composition. For example, a sole-like flexible ventral tarsal surface containing resilin is combined with sclerotized pseudo-claws. This likely enables the larvae to cope with surface structures on the spider's body, with substrates on the ground, and also with various structural elements in the spider's nest. The leg morphology is evaluated with respect to phylogenetic affinities. A trumpet-shaped, elongated empodium has likely evolved early in the evolution of Neuroptera and may consequently belong to the groundplan of a large subgroup of the order. It characterizes most groups of the hemerobiform lineage and is also present in the myrmeleontiform Psychopsidae. The presence of a tarsal protrusion resembling a pretarsus confirms the monophyletic origin of Mantispoidea. A single fixed tooth and a specific surface structure are potential autapomorphies of Mantispidae. A distal tibial subunit partly separated from the main part of the leg segment is an apomorphy only described for larvae of M. aphavexelte.
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Affiliation(s)
- Kenny Jandausch
- Institut für Zoologie und Evolutionsforschung, Friedrich-Schiller-Universität Jena, Jena, Germany
| | - Rolf G Beutel
- Institut für Zoologie und Evolutionsforschung, Friedrich-Schiller-Universität Jena, Jena, Germany
| | - Hans Pohl
- Institut für Zoologie und Evolutionsforschung, Friedrich-Schiller-Universität Jena, Jena, Germany
| | - Stanislav N Gorb
- Department of Functional Morphology and Biomechanics, Institute of Zoology, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
| | - Sebastian Büsse
- Department of Functional Morphology and Biomechanics, Institute of Zoology, Christian-Albrechts-Universität zu Kiel, Kiel, Germany.
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Voigt D, Gorb S. Functional morphology of tarsal adhesive pads and attachment ability in ticks Ixodes ricinus (Arachnida, Acari, Ixodidae). ACTA ACUST UNITED AC 2018; 220:1984-1996. [PMID: 28566356 DOI: 10.1242/jeb.152942] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Accepted: 03/16/2017] [Indexed: 11/20/2022]
Abstract
The presence of well-developed, elastic claws on ticks and widely pilose hosts led us to hypothesise that ticks are mostly adapted to attachment and locomotion on rough, strongly corrugated and hairy, felt-like substrates. However, by using a combination of morphological and experimental approaches, we visualised the ultrastructure of attachment devices of Ixodes ricinus and showed that this species adheres more strongly to smooth surfaces than to rough ones. Between paired, elongated, curved, elastic claws, I. ricinus bears a large, flexible, foldable adhesive pad, which represents an adaptation to adhesion on smooth surfaces. Accordingly, ticks attached strongest to glass and to surface profiles similar to those of the human skin, generating safety factors (attachment force relative to body weight) up to 534 (females). Considerably lower attachment force was found on silicone substrates and as a result of thanatosis after jolting.
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Affiliation(s)
- Dagmar Voigt
- Department of Functional Morphology and Biomechanics, Zoological Institute, Christian-Albrechts-Universität zu Kiel, Am Botanischen Garten 1-9, Kiel D-24098, Germany
| | - Stanislav Gorb
- Department of Functional Morphology and Biomechanics, Zoological Institute, Christian-Albrechts-Universität zu Kiel, Am Botanischen Garten 1-9, Kiel D-24098, Germany
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Büscher TH, Buckley TR, Grohmann C, Gorb SN, Bradler S. The Evolution of Tarsal Adhesive Microstructures in Stick and Leaf Insects (Phasmatodea). Front Ecol Evol 2018. [DOI: 10.3389/fevo.2018.00069] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
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Rebora M, Michels J, Salerno G, Heepe L, Gorb E, Gorb S. Tarsal attachment devices of the southern green stink bug Nezara viridula
(Heteroptera: Pentatomidae). J Morphol 2018; 279:660-672. [DOI: 10.1002/jmor.20801] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Revised: 01/26/2018] [Accepted: 01/28/2018] [Indexed: 12/14/2022]
Affiliation(s)
- Manuela Rebora
- Dipartimento di Chimica, Biologia e Biotecnologie; University of Perugia; Perugia 06121 Italy
| | - Jan Michels
- Department of Functional Morphology and Biomechanics; Zoological Institute, Kiel University; 24118 Kiel Germany
| | - Gianandrea Salerno
- Dipartimento di Scienze Agrarie, Alimentari e Ambientali; University of Perugia; Perugia Italy
| | - Lars Heepe
- Department of Functional Morphology and Biomechanics; Zoological Institute, Kiel University; 24118 Kiel Germany
| | - Elena Gorb
- Department of Functional Morphology and Biomechanics; Zoological Institute, Kiel University; 24118 Kiel Germany
| | - Stanislav Gorb
- Department of Functional Morphology and Biomechanics; Zoological Institute, Kiel University; 24118 Kiel Germany
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Persson BNJ, Kovalev A, Gorb SN. Simple contact mechanics model of the vertebrate cartilage. SOFT MATTER 2017; 13:6349-6362. [PMID: 28868539 DOI: 10.1039/c7sm00753a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
We study a simple contact mechanics model of the vertebrate cartilage, which includes (bulk) osmotic effects. The surface roughness power spectrum of a pig cartilage is obtained from the measured surface topography. Using the Reynolds equations with fluid flow factors, calculated using the Persson contact mechanics theory and the Bruggeman effective medium theory, we show how the area of contact and the average interfacial separation change with time. We found that in most cases the contact area percolates, resulting in islands of confined fluid which carry most of the external load. Most importantly, we find that the pressure in the area of real contact is nearly independent of the external load, and well below 1 MPa. This allows the surfaces in the area of "real contact", to be separated (at nanometer range separation distance) by osmotic repulsion, resulting in a very small (breakloose) friction force observed even after a long time of stationary contact.
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Schmitt C, Betz O. Morphology and ultrastructure of the tarsal adhesive organs of the Madagascar hissing cockroach Gromphadorhina portentosa. Cell Tissue Res 2017; 370:243-265. [DOI: 10.1007/s00441-017-2661-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2016] [Accepted: 06/15/2017] [Indexed: 01/05/2023]
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Betz O, Frenzel M, Steiner M, Vogt M, Kleemeier M, Hartwig A, Sampalla B, Rupp F, Boley M, Schmitt C. Adhesion and friction of the smooth attachment system of the cockroach Gromphadorhina portentosa and the influence of the application of fluid adhesives. Biol Open 2017; 6:589-601. [PMID: 28507055 PMCID: PMC5450327 DOI: 10.1242/bio.024620] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Accepted: 03/27/2017] [Indexed: 11/20/2022] Open
Abstract
Two different measurement techniques were applied to study the attachment of the smooth foot pads of the Madagascar hissing cockroach Gromphadorhina portentosa The attachment of the non-manipulated adhesive organs was compared with that of manipulated ones (depletion or substitution by artificial secretions). From measurements of the friction on a centrifuge, it can be concluded that on nanorough surfaces, the insect appears to benefit from employing emulsions instead of pure oils to avoid excessive friction. Measurements performed with a nanotribometer on single attachment organs showed that, in the non-manipulated euplantulae, friction was clearly increased in the push direction, whereas the arolium of the fore tarsus showed higher friction in the pull direction. The surface of the euplantulae shows an imbricate appearance, whereupon the ledges face distally, which might contribute to the observed frictional anisotropy in the push direction. Upon depletion of the tarsal adhesion-mediating secretion or its replacement by oily fluids, in several cases, the anisotropic effect of the euplantula disappeared due to the decrease of friction forces in push-direction. In the euplantulae, adhesion was one to two orders of magnitude lower than friction. Whereas the tenacity was slightly decreased with depleted secretion, it was considerably increased after artificial application of oily liquids. In terms of adhesion, it is concluded that the semi-solid consistence of the natural adhesion-mediating secretion facilitates the detachment of the tarsus during locomotion. In terms of friction, on smooth to nanorough surfaces, the insects appear to benefit from employing emulsions instead of pure oils to avoid excessive friction forces, whereas on rougher surfaces the tarsal fluid rather functions in improving surface contact by keeping the cuticle compliable and compensating surface asperities of the substratum.
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Affiliation(s)
- Oliver Betz
- Institut für Evolution und Ökologie, Universität Tübingen, Auf der Morgenstelle 28, Tübingen D-72076, Germany
| | - Melina Frenzel
- Institut für Evolution und Ökologie, Universität Tübingen, Auf der Morgenstelle 28, Tübingen D-72076, Germany
| | - Michael Steiner
- Institut für Evolution und Ökologie, Universität Tübingen, Auf der Morgenstelle 28, Tübingen D-72076, Germany
| | - Martin Vogt
- Institut für Evolution und Ökologie, Universität Tübingen, Auf der Morgenstelle 28, Tübingen D-72076, Germany
| | - Malte Kleemeier
- Fraunhofer-Institut für Fertigungstechnik und Angewandte Materialforschung, Wiener Str. 12, Bremen D-28359, Germany
| | - Andreas Hartwig
- Fraunhofer-Institut für Fertigungstechnik und Angewandte Materialforschung, Wiener Str. 12, Bremen D-28359, Germany
- Universität Bremen, Fachbereich 2 Biologie/Chemie, Leobener Str., Bremen 28359, Germany
| | - Benjamin Sampalla
- Institut für Evolution und Ökologie, Universität Tübingen, Auf der Morgenstelle 28, Tübingen D-72076, Germany
| | - Frank Rupp
- University Hospital Tübingen, Section Medical Materials Science and Technology, Osianderstr. 2-8, Tübingen D-72076, Germany
| | - Moritz Boley
- Institut für Evolution und Ökologie, Universität Tübingen, Auf der Morgenstelle 28, Tübingen D-72076, Germany
| | - Christian Schmitt
- Institut für Evolution und Ökologie, Universität Tübingen, Auf der Morgenstelle 28, Tübingen D-72076, Germany
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Persson BNJ. Contact mechanics for poroelastic, fluid-filled media, with application to cartilage. J Chem Phys 2016; 145:234703. [DOI: 10.1063/1.4972067] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Michels J, Appel E, Gorb SN. Functional diversity of resilin in Arthropoda. BEILSTEIN JOURNAL OF NANOTECHNOLOGY 2016; 7:1241-1259. [PMID: 27826498 PMCID: PMC5082342 DOI: 10.3762/bjnano.7.115] [Citation(s) in RCA: 75] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2016] [Accepted: 07/15/2016] [Indexed: 05/12/2023]
Abstract
Resilin is an elastomeric protein typically occurring in exoskeletons of arthropods. It is composed of randomly orientated coiled polypeptide chains that are covalently cross-linked together at regular intervals by the two unusual amino acids dityrosine and trityrosine forming a stable network with a high degree of flexibility and mobility. As a result of its molecular prerequisites, resilin features exceptional rubber-like properties including a relatively low stiffness, a rather pronounced long-range deformability and a nearly perfect elastic recovery. Within the exoskeleton structures, resilin commonly forms composites together with other proteins and/or chitin fibres. In the last decades, numerous exoskeleton structures with large proportions of resilin and various resilin functions have been described. Today, resilin is known to be responsible for the generation of deformability and flexibility in membrane and joint systems, the storage of elastic energy in jumping and catapulting systems, the enhancement of adaptability to uneven surfaces in attachment and prey catching systems, the reduction of fatigue and damage in reproductive, folding and feeding systems and the sealing of wounds in a traumatic reproductive system. In addition, resilin is present in many compound eye lenses and is suggested to be a very suitable material for optical elements because of its transparency and amorphousness. The evolution of this remarkable functional diversity can be assumed to have only been possible because resilin exhibits a unique combination of different outstanding properties.
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Affiliation(s)
- Jan Michels
- Department of Functional Morphology and Biomechanics, Institute of Zoology, Christian-Albrechts-Universität zu Kiel, Am Botanischen Garten 1–9, D-24118 Kiel, Germany
| | - Esther Appel
- Department of Functional Morphology and Biomechanics, Institute of Zoology, Christian-Albrechts-Universität zu Kiel, Am Botanischen Garten 1–9, D-24118 Kiel, Germany
| | - Stanislav N Gorb
- Department of Functional Morphology and Biomechanics, Institute of Zoology, Christian-Albrechts-Universität zu Kiel, Am Botanischen Garten 1–9, D-24118 Kiel, Germany
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Eshel-Green T, Eliyahu S, Avidan-Shlomovich S, Bianco-Peled H. PEGDA hydrogels as a replacement for animal tissues in mucoadhesion testing. Int J Pharm 2016; 506:25-34. [PMID: 27084292 DOI: 10.1016/j.ijpharm.2016.04.019] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Revised: 04/10/2016] [Accepted: 04/11/2016] [Indexed: 10/21/2022]
Abstract
Utilization of animal parts in ex-vivo mucoadhesion assays is a common approach that presents many difficulties due to animal rights issues and large variance between animals. This study examines the suitability of two PEGDA (poly(ethylene glycol) diacrylate) based hydrogels to serve as tissue mimetics for mucoadhesion evaluation. One hydrogel, termed PEGDA-QT, was composed of pentaerythritol tetrakis (3-mercaptopropionate) and PEG and contained free thiol groups mimicking those found in natural mucosa. The other hydrogel was formed by UV (ultraviolet) curing of PEGDA and mimicked the mechanical property of mucosa but not its chemical constitute. When ranking different first generation mucoadhesive polymers using a tensile assay, both hydrogels showed good agreement with the ranking achieved for porcine small intestine. However, only PEGDA-QT and porcine small intestine shared a similar displacement curve. The same ranking for PEGDA-QT and porcine small intestine was also observed when comparing a second-generation mucoadhesive polymer, thiolated alginate, to native alginate. Our findings suggest that PEGDA-QT could serve as a replacement for porcine small intestine in both mucoadhesion evaluations using a tensile machine and the flow-through method for first and second-generation mucoadhesive polymers.
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Affiliation(s)
- Tal Eshel-Green
- The Russell Berrie Nanotechnology Institute, Technion-Israel Institute of Technology, Haifa 32000, Israel
| | - Shaked Eliyahu
- The Russell Berrie Nanotechnology Institute, Technion-Israel Institute of Technology, Haifa 32000, Israel
| | | | - Havazelet Bianco-Peled
- The Russell Berrie Nanotechnology Institute, Technion-Israel Institute of Technology, Haifa 32000, Israel; Department of Chemical Engineering, Technion-Israel Institute of Technology, Haifa 32000, Israel.
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41
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Grohmann C, Henze MJ, Nørgaard T, Gorb SN. Two functional types of attachment pads on a single foot in the Namibia bush cricket Acanthoproctus diadematus (Orthoptera: Tettigoniidae). Proc Biol Sci 2016. [PMID: 26213740 DOI: 10.1098/rspb.2014.2976] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Insects have developed different structures to adhere to surfaces. Most common are smooth and hairy attachment pads, while nubby pads have also been described for representatives of Mantophasmatodea, Phasmida and Plecoptera. Here we report on the unusual combination of nubby and smooth tarsal attachment structures in the !nara cricket Acanthoproctus diadematus. Their three proximal tarsal pads (euplantulae) have a nubby surface, whereas the most distal euplantula is rather smooth with a hexagonal ground pattern resembling that described for the great green bush-cricket Tettigonia viridissima. This is, to our knowledge, the first report on nubby euplantulae in Orthoptera and the co-occurrence of nubby and smooth euplantulae on a single tarsus in a polyneopteran species. When adhering upside down to a horizontal glass plate, A. diadematus attaches its nubby euplantulae less often, compared to situations in which the animal is hanging upright or head down on a vertical plate. We discuss possible reasons for this kind of clinging behaviour, such as morphological constrains, the different role of normal and shear forces in attachment enhancement of the nubby and smooth pads, ease of the detachment process, and adaptations to walking on cylindrical substrates.
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Kleinteich T, Gorb SN. Frog tongue surface microstructures: functional and evolutionary patterns. BEILSTEIN JOURNAL OF NANOTECHNOLOGY 2016; 7:893-903. [PMID: 27547606 PMCID: PMC4979896 DOI: 10.3762/bjnano.7.81] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2016] [Accepted: 06/06/2016] [Indexed: 05/12/2023]
Abstract
Frogs (Lissamphibia: Anura) use adhesive tongues to capture fast moving, elusive prey. For this, the tongues are moved quickly and adhere instantaneously to various prey surfaces. Recently, the functional morphology of frog tongues was discussed in context of their adhesive performance. It was suggested that the interaction between the tongue surface and the mucus coating is important for generating strong pull-off forces. However, despite the general notions about its importance for a successful contact with the prey, little is known about the surface structure of frog tongues. Previous studies focused almost exclusively on species within the Ranidae and Bufonidae, neglecting the wide diversity of frogs. Here we examined the tongue surface in nine different frog species, comprising eight different taxa, i.e., the Alytidae, Bombinatoridae, Megophryidae, Hylidae, Ceratophryidae, Ranidae, Bufonidae, and Dendrobatidae. In all species examined herein, we found fungiform and filiform papillae on the tongue surface. Further, we observed a high degree of variation among tongues in different frogs. These differences can be seen in the size and shape of the papillae, in the fine-structures on the papillae, as well as in the three-dimensional organization of subsurface tissues. Notably, the fine-structures on the filiform papillae in frogs comprise hair-like protrusions (Megophryidae and Ranidae), microridges (Bufonidae and Dendrobatidae), or can be irregularly shaped or absent as observed in the remaining taxa examined herein. Some of this variation might be related to different degrees of adhesive performance and may point to differences in the spectra of prey items between frog taxa.
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Affiliation(s)
- Thomas Kleinteich
- Functional Morphology and Biomechanics, Zoology Department, Kiel University, 24118 Kiel, Germany
| | - Stanislav N Gorb
- Functional Morphology and Biomechanics, Zoology Department, Kiel University, 24118 Kiel, Germany
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Zurek DB, Gorb SN, Voigt D. Locomotion and attachment of leaf beetle larvae Gastrophysa viridula (Coleoptera, Chrysomelidae). Interface Focus 2015; 5:20140055. [PMID: 25657837 DOI: 10.1098/rsfs.2014.0055] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
While adult green dock leaf beetles Gastrophysa viridula use tarsal adhesive setae to attach to and walk on smooth vertical surfaces and ceilings, larvae apply different devices for similar purposes: pretarsal adhesive pads on thoracic legs and a retractable pygopod at the 10th abdominal segment. Both are soft smooth structures and capable of wet adhesion. We studied attachment ability of different larval instars, considering the relationship between body weight and real contact area between attachment devices and the substrate. Larval gait patterns were analysed using high-speed video recordings. Instead of the tripod gait of adults, larvae walked by swinging contralateral legs simultaneously while adhering by the pygopod. Attachment ability of larval instars was measured by centrifugation on a spinning drum, revealing that attachment force decreases relative to weight. Contributions of different attachment devices to total attachment ability were investigated by selective disabling of organs by covering them with melted wax. Despite their smaller overall contact area, tarsal pads contributed to a larger extent to total attachment ability, probably because of their distributed spacing. Furthermore, we observed different behaviour in adults and larvae when centrifuged: while adults gradually slipped outward on the centrifuge drum surface, larvae stayed at the initial position until sudden detachment.
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Affiliation(s)
- Daniel B Zurek
- Evolutionary Biomaterials Group, Department of Thin Films and Biological Systems , Max Planck Institute for Intelligent Systems , Heisenbergstraße 03, 70569 Stuttgart , Germany
| | - Stanislav N Gorb
- Evolutionary Biomaterials Group, Department of Thin Films and Biological Systems , Max Planck Institute for Intelligent Systems , Heisenbergstraße 03, 70569 Stuttgart , Germany ; Functional Morphology and Biomechanics, Zoological Institute , Christian-Albrechts-Universität zu Kiel , Am Botanischen Garten 1-9, 24098 Kiel , Germany
| | - Dagmar Voigt
- Evolutionary Biomaterials Group, Department of Thin Films and Biological Systems , Max Planck Institute for Intelligent Systems , Heisenbergstraße 03, 70569 Stuttgart , Germany ; Functional Morphology and Biomechanics, Zoological Institute , Christian-Albrechts-Universität zu Kiel , Am Botanischen Garten 1-9, 24098 Kiel , Germany
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Drotlef DM, Appel E, Peisker H, Dening K, Del Campo A, Gorb SN, Barnes WJP. Morphological studies of the toe pads of the rock frog, Staurois parvus (family: Ranidae) and their relevance to the development of new biomimetically inspired reversible adhesives. Interface Focus 2015; 5:20140036. [PMID: 25657830 DOI: 10.1098/rsfs.2014.0036] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The morphology of the toe epithelium of the rock frog, Staurois parvus (Family Ranidae), was investigated using a variety of microscopical techniques. The toe pad epithelium is stratified (four to five cell layers), the apical parts of the cells of the outermost layer being separated by fluid-filled channels. The surface of these cells is covered by a dense array of nanopillars, which also cover the surface of subarticular tubercles and unspecialized ventral epithelium of the toes, but not the dorsal epithelium. The apical portions of the outer two layers contain fibrils that originate from the nanopillars and are oriented approximately normal to the surface. This structure is similar to the pad structure of tree frogs of the families Hylidae and Rhacophoridae, indicating evolutionary convergence and a common evolutionary design for reversible attachment in climbing frogs. The main adaptation to the torrent habitat seems to be the straightness of the channels crossing the toe pad, which will assist in drainage of excess water. The presence of nanopillar arrays on all ventral surfaces of the toes resembles that on clingfish suckers and may be a specific adaptation for underwater adhesion and friction. The relevance of these findings to the development of new biomimetically inspired reversible adhesives is discussed.
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Affiliation(s)
- Dirk M Drotlef
- Max Planck Institut für Polymerforschung , Mainz , Germany
| | - Esther Appel
- Functional Morphology and Biomechanics , University of Kiel , Kiel , Germany
| | - Henrik Peisker
- Functional Morphology and Biomechanics , University of Kiel , Kiel , Germany
| | - Kirstin Dening
- Functional Morphology and Biomechanics , University of Kiel , Kiel , Germany
| | | | - Stanislav N Gorb
- Functional Morphology and Biomechanics , University of Kiel , Kiel , Germany
| | - W Jon P Barnes
- Centre for Cell Engineering , University of Glasgow , Scotland , UK
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Zheden V, Klepal W, Gorb SN, Kovalev A. Mechanical properties of the cement of the stalked barnacle Dosima fascicularis (Cirripedia, Crustacea). Interface Focus 2015; 5:20140049. [PMID: 25657833 PMCID: PMC4275868 DOI: 10.1098/rsfs.2014.0049] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The stalked barnacle Dosima fascicularis secretes foam-like cement, the amount of which usually exceeds that produced by other barnacles. When Dosima settles on small objects, this adhesive is additionally used as a float which gives buoyancy to the animal. The dual use of the cement by D. fascicularis requires mechanical properties different from those of other barnacle species. In the float, two regions with different morphological structure and mechanical properties can be distinguished. The outer compact zone with small gas-filled bubbles (cells) is harder than the interior one and forms a protective rind presumably against mechanical damage. The inner region with large, gas-filled cells is soft. This study demonstrates that D. fascicularis cement is soft and visco-elastic. We show that the values of the elastic modulus, hardness and tensile stress are considerably lower than in the rigid cement of other barnacles.
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Affiliation(s)
- Vanessa Zheden
- Faculty of Life Sciences, Core Facility Cell Imaging and Ultrastructure Research , University of Vienna , Vienna , Austria
| | - Waltraud Klepal
- Faculty of Life Sciences, Core Facility Cell Imaging and Ultrastructure Research , University of Vienna , Vienna , Austria
| | - Stanislav N Gorb
- Zoological Institute: Functional Morphology and Biomechanics , Kiel University , Kiel , Germany
| | - Alexander Kovalev
- Zoological Institute: Functional Morphology and Biomechanics , Kiel University , Kiel , Germany
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Interlocking-based attachment during locomotion in the beetle Pachnoda marginata (Coleoptera, Scarabaeidae). Sci Rep 2014; 4:6998. [PMID: 25385502 PMCID: PMC4227028 DOI: 10.1038/srep06998] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2014] [Accepted: 10/23/2014] [Indexed: 11/29/2022] Open
Abstract
The attachment function of tibial spurs and pretarsal claws in the beetle Pachnoda marginata (Coleoptera, Scarabaeidae) during locomotion was examined in this study. First, we measured the angle, at which the beetles detached from substrates with different roughness. At a surface roughness of 12 μm and higher, intact animals were able to cling to a completely tilted platform (180°). Second, we estimated the forces the beetles could exert in walking on smooth and rough cylinders of different diameters, on a plane and also between two plates. To elucidate the role of the individual structures, we ablated them consecutively. We found tibial spurs not to be in use in walking on flat substrates. On some of the curved substrates, ablation of tibial spurs caused an effect. A clear effect of tibial spurs was revealed in walking between two plates. Thus, these structures are probably used for generating propulsion in narrowed spaces.
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Bennemann M, Backhaus S, Scholz I, Park D, Mayer J, Baumgartner W. Determination of the Young's modulus of the epicuticle of the smooth adhesive organs of Carausius morosus using tensile testing. J Exp Biol 2014; 217:3677-87. [PMID: 25214493 PMCID: PMC4198382 DOI: 10.1242/jeb.105114] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2014] [Accepted: 08/07/2014] [Indexed: 11/20/2022]
Abstract
Adhesive organs like arolia of insects allow these animals to climb on different substrates by creating high adhesion forces. According to the Dahlquist criterion, adhesive organs must be very soft, exhibiting an effective Young's modulus of below 100 kPa to adhere well to substrates. Such a low effective Young's modulus allows the adhesive organs to make almost direct contact with the substrate and results in van der Waals forces along with capillary forces. In previous studies, the effective Young's moduli of adhesive organs were determined using indentation tests, revealing their structure to be very soft. However, adhesive organs show a layered structure, thus the measured values comprise the effective Young's moduli of several layers of the adhesive organs. In this study, a new approach is illustrated to measure the Young's modulus of the outermost layer of the arolium, i.e. of the epicuticle, of the stick insect Carausius morosus. As a result of the epicuticle being supported by upright fibres, tensile tests allow the determination of the Young's modulus of the epicuticle with hardly influence from subjacent layers. In our tensile tests, arolia of stick insects adhering on a latex membrane were stretched by stretching the membrane while the elongation of the contact area between an arolium and the membrane was recorded. For analysis, mathematical models of the mechanical system were developed. When fed with the observed elongations, these models yield estimates for the Young's modulus of the epicuticle of approximately 100 MPa. Thus, in arolia, a very thin layer (~225 nm) of a rather stiff material, which is less susceptible to abrasion, makes contact with the substrates, whereas the inner fibrous structure of arolia is responsible for their softness.
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Affiliation(s)
- Michael Bennemann
- Department Cellular Neurobionics, Institute for Biology II, RWTH Aachen University, Worringerweg 3, 52074 Aachen, Germany Westfälisches Institut für Bionik, Westfälische Hochschule Gelsenkirchen Bocholt Recklinghausen, Münsterstraße 265, 46397 Bocholt, Germany
| | - Stefan Backhaus
- Department Cellular Neurobionics, Institute for Biology II, RWTH Aachen University, Worringerweg 3, 52074 Aachen, Germany
| | - Ingo Scholz
- Department Cellular Neurobionics, Institute for Biology II, RWTH Aachen University, Worringerweg 3, 52074 Aachen, Germany
| | - Daesung Park
- Central Facility for Electron Microscopy, RWTH Aachen University, Ahornstraße 55, 52074 Aachen, Germany
| | - Joachim Mayer
- Central Facility for Electron Microscopy, RWTH Aachen University, Ahornstraße 55, 52074 Aachen, Germany
| | - Werner Baumgartner
- Department Cellular Neurobionics, Institute for Biology II, RWTH Aachen University, Worringerweg 3, 52074 Aachen, Germany Institute of Biomedical Mechatronics, University of Linz, Altenbergerstraße 69, 4040 Linz, Austria
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HOST B, TWYFFELS L, ROISIN Y, VANDERWINDEN JM. Three-dimensional visualization of termite (Apicotermitinae) enteric valve using confocal laser scanning microscopy. J Microsc 2014; 255:116-22. [DOI: 10.1111/jmi.12146] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2013] [Accepted: 05/10/2014] [Indexed: 11/27/2022]
Affiliation(s)
- B. HOST
- Evolutionary Biology and Ecology; Faculté des Sciences; Université Libre de Bruxelles; Brussels Belgium
| | - L. TWYFFELS
- Molecular Biology of the Gene Laboratory and Center of Microscopy and Molecular Imaging; Faculté des Sciences; Université Libre de Bruxelles; Brussels Belgium
| | - Y. ROISIN
- Evolutionary Biology and Ecology; Faculté des Sciences; Université Libre de Bruxelles; Brussels Belgium
| | - J.-M. VANDERWINDEN
- Laboratory of Neurophysiology and Light Microscopy Facility; Faculté de Médecine; Université Libre de Bruxelles; Brussels Belgium
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Gorb SN, Filippov AE. Fibrillar adhesion with no clusterisation: Functional significance of material gradient along adhesive setae of insects. BEILSTEIN JOURNAL OF NANOTECHNOLOGY 2014; 5:837-45. [PMID: 24991520 PMCID: PMC4077360 DOI: 10.3762/bjnano.5.95] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2014] [Accepted: 05/15/2014] [Indexed: 05/26/2023]
Abstract
It has been recently demonstrated that adhesive tarsal setae of beetles possess material gradients along their length. These gradients presumably represent an evolutionary optimization enhancing the adaptation to rough surfaces while simultaneously preventing clusterisation of the setae by lateral collapse. The numerical experiment of the present study has clearly demonstrated that gradient-bearing fibers with short soft tips and stiff bases have greater advantage in maximizing adhesion and minimizing clusterisation in multiple attachment-detachment cycles, if compared to the fibers with longer soft tips on the stiff bases and fibers with stiff tips on the soft bases. This study not only manifests the crucial role of gradients in material properties along the setae in beetle fibrillar adhesive system, but predicts that similar gradients must have been convergently evolved in various lineages of arthropods.
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Affiliation(s)
- Stanislav N Gorb
- Department Functional Morphology and Biomechanics, Zoological Institute of the Kiel University, Am Botanischen Garten 1–9, D-24098 Kiel, Germany
| | - Alexander E Filippov
- Donetsk Institute for Physics and Engineering, National Academy of Sciences of Ukraine, Donetsk, Ukraine
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