Labisch, Susanna
Lade...
10 Ergebnisse
Einstellungen
Gerade angezeigt 1 - 10 von 10
- Some of the metrics are blocked by yourconsent settings
Item-typ:Veröffentlichung, The ultrastructure of the starfish skeleton is correlated with mechanical stressEchinoderms and vertebrates both possess mesodermal endoskeletons. In vertebrates, the response to mechanical loads and the capacity to remodel the ultrastructure of the skeletal system are fundamental attributes of their endoskeleton. To determine whether these characteristics are also inherent in Echinoderms, we conducted a comprehensive biomechanical and morphological study on the endoskeleton of Asterias rubens, a representative model organism for Echinoderm skeletons. Our analysis involved high-resolution X-ray CT scans of entire individual ossicles, covering the full stereom distribution along with the attached muscles. Leveraging this data, we conducted finite element analysis to explore the correlation between mechanical loads acting on an ossicle and its corresponding stereom structure. To understand the effects of localized stress concentration, we examined stereom regions subjected to high mechanical stress and compared them to areas with lower mechanical stress. Our results show that the stereom microstructure, both in terms of thickness and orientation, corresponds closely to the mechanical loading experienced by the ossicles. Additionally, by comparing the stereom structures of ossicles in various developmental stages, we assessed the general remodeling capacity of these ossicles. Our findings suggest that the ability to adapt to mechanical loads is a common feature of mesoderm endoskeletons within the Deuterostomia taxonomic group. However, the material remodelling may be a specific trait unique to vertebrate endoskeletons.Wissenschaftlicher ArtikelBand:19331 - Some of the metrics are blocked by yourconsent settings
Item-typ:Veröffentlichung, 16 - Some of the metrics are blocked by yourconsent settings
Item-typ:Veröffentlichung, 3D escape: an alternative paradigm for spatial orientation studies in insectsArthropods and in particular insects show a great variety of different exoskeletal sensors. For most arthropods, spatial orientation and gravity perception is not fully understood. In particular, the interaction of the different sensors is still a subject of ongoing research. A disadvantage of most of the experimental methods used to date to study the spatial orientation of arthropods in behavioral experiments is that the body or individual body parts are fixed partly in a non-natural manner. Therefore, often only the movement of individual body segments can be used to evaluate the experiments. We here present a novel experimental method to easily study 3D-escape movements in insects and analyze whole-body reaction. The animals are placed in a transparent container, filled with a lightweight substrate and rotating around two axes. To verify our setup, house crickets (Acheta domesticus) with selectively manipulated gravity-perceiving structures were analyzed. The spatial orientation behavior was quantified by measuring the time individuals took to escape toward the surface and the angular deviation toward the gravitational vector. These experiments confirm earlier results and therefore validated our experimental setup. Our new approach thus allows to investigate several comprehensive questions regarding the spatial orientation of insects and other animals.Wissenschaftlicher Artikel142 - Some of the metrics are blocked by yourconsent settings
Item-typ:Veröffentlichung, Cuticular microstructure of the locust femur–tibia joint(The Company of Biologists, 2025-07-15); ; In insect exoskeletons, articular membranes connect the sclerotized hard segments within joints, ensuring protection, mobility, and resilience to mechanical stresses. During exoskeletal movement, these membranes experience tensile and compressive forces, leading to either stretching or the formation of cuticular folds. The mechanisms underlying cuticular folding remain unclear, particularly whether folds are regular (specific) or irregular (non-specific) and how cuticle ultrastructure influences folding patterns. To address these questions, we examined the femur–tibia joints in the mesothoracic legs of locusts (Locusta migratoria) using non-destructive micro-CT, histological methods, and scanning electron microscopy. The joints were analyzed at different flexion angles and maturity stages to characterize membrane folding. Our findings reveal distinct scales of cuticular folds in the femur–tibia joint: macrofolds associated with internal structures such as muscle attachment sites and microfolds potentially linked to cuticle ultrastructure, surface properties, or membrane thickness differences.Wissenschaftlicher ArtikelBand:14Heft:742 - Some of the metrics are blocked by yourconsent settings
Item-typ:Veröffentlichung, Structure-property relationships in Japanese knotweed – The potential of using the stem for composite applications(Elsevier Science, 2022); ; ; ; The Japanese perennial knotweed (Fallopia japonica) is a globally widespread neophyte whose usability is being investigated, e.g., to use knotweed for biogas plants and as a substitute for firewood. The present study investigates the potential of Japanese knotweed for material use. Morphological studies were carried out on the stem cell structures and arrangements (microstructure) and the external stem structure (macrostructure) and showed that Japanese knotweed is a plant species with several hierarchical morphological levels being a highly complex fibre-matrix composite with a low density. Mechanical properties were investigated using tensile, bending, compression and impact tests for fresh and dry specimens and then mathematically converted in density-related lightweight construction indices and compared with other materials using Ashby maps. Particularly under compression, properties are close to woods and wood composites, making the plant an interesting material for lightweight sandwich panels, where assembled slices of the stalk could serve as core elements. Fibre bundles, extracted from the stalk, show relatively low mechanical properties (tensile strength: 93 MPa; Young’s modulus: 4.77 GPa) compared to bast fibres such as hemp. The shredded stalks could be compounded into homogeneous granulates directly after harvesting without other separation processes. Therefore, the study presents a proof of concept for Japanese knotweed to apply the shredded stalks in injection-moulded PLA composites (tensile strength: mean = 54 MPa; Young’s modulus: mean = 5.61 GPa) comparable or even better than wood fibre-reinforced polymers.Wissenschaftlicher ArtikelHeft:186136 - Some of the metrics are blocked by yourconsent settings
Item-typ:Veröffentlichung, Biomimetic tag attachment inspired by the seal louseSatellite telemetry is widely used to study the movements of marine mammals, but current attachment methods for seals typically rely on epoxy adhesives, which pose risks to animal welfare and the marine environment. This study presents a biomimetic, adhesive-free attachment system inspired by the seal louse Echinophthirius horridus, an ectoparasite capable of maintaining a strong grip on seal fur in aquatic conditions. A top–down biomimetic approach was used to abstract key functional principles from the louse’s claw morphology and cuticular anchoring structures. These biological features informed the development of a 3D-printed comb-clamp prototype, termed ‘TACS’ (Transmitter Attachment Clamp[s]), designed specifically for the hair structure of harbour seals. Microscopy and x-ray microtomography revealed morphological traits such as interlocking setae, directional grooves, and a specialised euplantula, which were functionally integrated into the prototype. Tensile tests on tanned seal fur demonstrated mean maximum retention forces of 4.58 N under dry conditions and 2.42 N under wet conditions. A proof-of-concept trial on a live harbour seal showed successful attachment for up to 50 min, without signs of distress or fur damage. The TACS system fulfilled key design criteria: rapid and reversible application, low material weight (<20 g), and strong mechanical retention without the use of adhesives. This study demonstrates the potential of biologically inspired design to provide an environmentally responsible alternative to conventional tagging methods and highlights the relevance of E. horridus as a functional model for bioinspired gripping systems in marine applications.Wissenschaftlicher ArtikelBand:20Heft:660 - Some of the metrics are blocked by yourconsent settings
Item-typ:Veröffentlichung, What goes up must come down: biomechanical impact analysis of falling locustsMany insects are able to precisely control their jumping movements. Once in the air, the properties of the actual landing site, however, are almost impossible to predict. Falling insects thus have to cope with the situation at impact. In particular, for insects jumping to escape predators, a controlled landing movement appears to be a major evolutionary advantage. A quick recovery into an upright and stable body posture minimizes the time to prepare for the next escape jump. In this study, we used high-speed recordings to investigate the falling and in particular the impact behavior of Schistocerca gregaria locusts, a common model organism for studies on the biomechanics of jumping. Detailed impact analyses of free-falling locusts show that most insects typically crashed onto the substrate. Although free-falling locusts tended to spread their legs, they mostly fell onto the head and thorax first. The presence of wings did not significantly reduce impact speed; however, it did affect the orientation of the body at impact and significantly reduced the time to recover. Our results also show that alive warm locusts fell significantly faster than inactive or dead locusts. This indicates a possible tradeoff between active control versus reduced speed. Interestingly, alive insects also tended to perform a characteristic bending movement of the body at impact. This biomechanical adaptation might reduce the rebound and shorten the time to recover. The adhesive pads also play an important role in reducing the time to recover by allowing the insect to anchor itself to the substrate.Wissenschaftlicher ArtikelBand:222Heft:14188 - Some of the metrics are blocked by yourconsent settings
Item-typ:Veröffentlichung, A starfish-inspired 4D self-healing morphing structureInspired by the starfish's unique ability to achieve flexibility and posture-holding with minimal energy expenditure, we present a novel bioinspired morphing structure. Our two-component design, consisting of a thermoplastic mesh and elastomeric jacket, effectively mimics the functions of the starfish's ossicles, mutable collagenous tissues, and derma. This structure exhibits a remarkable combination of self-healing, time-dependent shape memory, and self-posture-holding properties. Systematic variations in mesh geometry demonstrate precise control over structural stiffness and thermal response, enabling customization for specific applications. The structure's scalability and ease of fabrication further enhance its adaptability. We experimentally demonstrate the potential of our biomimetic morphing structure using several prototypes. This work lays the foundation for developing a new type of versatile morphing structures with applications in diverse fields, including robotics, biomedical devices, and adaptive structures.Wissenschaftlicher ArtikelBand:14103 - Some of the metrics are blocked by yourconsent settings
Item-typ:Veröffentlichung, The biomechanical dilemma of phasmid eggs – how do stick insects hatch?(The Company of Biologists, 2025-09); ; During their development, phasmid eggs with their long developmental periods face numerous biotic and abiotic challenges. These insect eggs are unique for their thick egg capsule and a specialised escape structure called the operculum/lid. This operculum needs to be easy to open from the inside, yet must not be a ‘weak spot’ for potential predators. One possible solution to this biomechanical dilemma could be a change in the operculum's mechanical properties over time. To investigate this hypothesis, we analysed the effect of age and storage conditions on the biomechanical properties of the egg and the operculum. We also performed high-resolution X-ray microscopy (XRM) and synchrotron studies to analyse the ultrastructure of the eggshell and operculum. Our results show that the eggs of Carausius morosus were able to resist a compressive force of up to 2 N. During maturation, the force required to open the operculum was significantly reduced from 0.14 N to 0.09 N. The properties of the eggshell itself, however, were not affected by humidity and did not change during maturation. Interestingly, the egg properties were affected by the mother's age. Our results thus indicate that the operculum is not a primary fracture site for externally applied stress; however, structural changes in the operculum during the developmental process of the embryo facilitate the hatching process.Wissenschaftlicher ArtikelBand:228Heft:1853 - Some of the metrics are blocked by yourconsent settings
Item-typ:Veröffentlichung, SAUV-A Bio-Inspired Soft-Robotic Autonomous Underwater VehicleAutonomous and remotely operated underwater vehicles allow us to reach places which have previously been inaccessible and perform complex repair, exploration and analysis tasks. As their navigation is not infallible, they may cause severe damage to themselves and their often fragile surroundings, such as flooded caves, coral reefs, or even accompanying divers in case of a collision. In this study, we used a shallow neural network, consisting of interlinking PID controllers, and trained by a genetic algorithm, to control a biologically inspired AUV with a soft and compliant exoskeleton. Such a compliant structure is a versatile and passive solution which reduces the accelerations induced by collisions to 56% of the original mean value acting upon the system, thus, notably reducing the stress on its components and resulting reaction forces on its surroundings. The segmented structure of this spherical exoskeleton protects the encased system without limiting the use of cameras, sensors or manipulators.Wissenschaftlicher ArtikelBand:14151