Editor's Choice Articles

Editor’s Choice articles are based on recommendations by the scientific editors of MDPI journals from around the world. Editors select a small number of articles recently published in the journal that they believe will be particularly interesting to readers, or important in the respective research area. The aim is to provide a snapshot of some of the most exciting work published in the various research areas of the journal.

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Article
Gradient Micropillar Array Inspired by Tree Frog for Robust Adhesion on Dry and Wet Surfaces
Biomimetics 2022, 7(4), 209; https://doi.org/10.3390/biomimetics7040209 - 21 Nov 2022
Viewed by 697
Abstract
The strong adhesion on dry and wet surfaces and the durability of bioinspired hierarchical fibrillar adhesives are critical for their applications. However, the critical design for the strong adhesion normally depends on fine sub-micron structures which could be damaged during repeat usage. Here, [...] Read more.
The strong adhesion on dry and wet surfaces and the durability of bioinspired hierarchical fibrillar adhesives are critical for their applications. However, the critical design for the strong adhesion normally depends on fine sub-micron structures which could be damaged during repeat usage. Here, we develop a tree frog-inspired gradient composite micropillars array (GP), which not only realizes a 2.3-times dry adhesion and a 5.6-times wet adhesion as compared to the pure polydimethylsiloxane (PDMS) micropillars array (PP), but also shows excellent durability over 200 repeating cycles of attachment/detachment and self-cleaning ability. A GP consists of stiffer tips and softer roots by incorporating gradient dispersed CaCO3 nanoparticles in PDMS micropillar stalks. The modulus gradient along the micropillar height facilitates the contact formation and enhances the maximum stress during the detaching. The study here provides a new design strategy for robust adhesives for practical applications in the fields of robotics, electronics, medical engineering, etc. Full article
(This article belongs to the Special Issue Bioinspired Functional Surfaces)
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Article
Serval Optimization Algorithm: A New Bio-Inspired Approach for Solving Optimization Problems
Biomimetics 2022, 7(4), 204; https://doi.org/10.3390/biomimetics7040204 - 20 Nov 2022
Viewed by 687
Abstract
This article introduces a new metaheuristic algorithm called the Serval Optimization Algorithm (SOA), which imitates the natural behavior of serval in nature. The fundamental inspiration of SOA is the serval’s hunting strategy, which attacks the selected prey and then hunts the prey in [...] Read more.
This article introduces a new metaheuristic algorithm called the Serval Optimization Algorithm (SOA), which imitates the natural behavior of serval in nature. The fundamental inspiration of SOA is the serval’s hunting strategy, which attacks the selected prey and then hunts the prey in a chasing process. The steps of SOA implementation in two phases of exploration and exploitation are mathematically modeled. The capability of SOA in solving optimization problems is challenged in the optimization of thirty-nine standard benchmark functions from the CEC 2017 test suite and CEC 2019 test suite. The proposed SOA approach is compared with the performance of twelve well-known metaheuristic algorithms to evaluate further. The optimization results show that the proposed SOA approach, due to the appropriate balancing exploration and exploitation, is provided better solutions for most of the mentioned benchmark functions and has superior performance compared to competing algorithms. SOA implementation on the CEC 2011 test suite and four engineering design challenges shows the high efficiency of the proposed approach in handling real-world optimization applications. Full article
(This article belongs to the Special Issue Bio-Inspired Design and Optimisation of Engineering Systems)
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Article
Enhanced Adhesion of Synthetic Discs with Micro-Patterned Margins
Biomimetics 2022, 7(4), 202; https://doi.org/10.3390/biomimetics7040202 - 18 Nov 2022
Viewed by 697
Abstract
Many aquatic creatures in nature have non-cooperative surface scaling abilities using suction organs; micro-/nano-scale structures found in different parts of the organs play an important role in this mechanism. Synthetic bioinspired suction devices have been developed, but the mechanisms of bioinspired suction system [...] Read more.
Many aquatic creatures in nature have non-cooperative surface scaling abilities using suction organs; micro-/nano-scale structures found in different parts of the organs play an important role in this mechanism. Synthetic bioinspired suction devices have been developed, but the mechanisms of bioinspired suction system need further investigation. This paper presents the development of a synthetic adhesive disc inspired by the hillstream loach. The microscopic structures involved in adhesion of the hillstream loach were investigated. Bioinspired suction discs were designed with single-level or hierarchical micropatterned margins. Micro three-dimensional (3D) printing and micro electromechanical system (MEMs) technology were utilized in the fabrication of the discs, and the adhesion performance was tested on substrates with different roughness values. The engaging and disengaging processes of the margin were simulated by carrying out a peeling test on a submerged substrate. The interactions between the liquid film and the microstructures were observed using fluorescence microscopy. The enhanced adhesion forces due to the synergy of the hierarchically micro-patterned margin and the disc cavity were duplicated in the synthetic adhesion system. Full article
(This article belongs to the Special Issue Biological Adhesives: From Biology to Biomimetics)
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Article
Theoretical Design of a Bionic Spatial 3D-Arrayed Multifocal Metalens
Biomimetics 2022, 7(4), 200; https://doi.org/10.3390/biomimetics7040200 - 16 Nov 2022
Viewed by 672
Abstract
With the development of micro/nano-optics, metasurfaces are gaining increasing attention working as novel electromagnetic wave control devices. Among which, metalenses have been developed and applied as a typical application of metasurfaces owing to their unique optical properties. However, most of those previous metalenses [...] Read more.
With the development of micro/nano-optics, metasurfaces are gaining increasing attention working as novel electromagnetic wave control devices. Among which, metalenses have been developed and applied as a typical application of metasurfaces owing to their unique optical properties. However, most of those previous metalenses can only produce one focal point, which severely limits their applications. Inspired by the fly compound eye, we propose a special kind of spatial multifocal metalens. Our metalenses can reverse the polarization state of the incident circularly polarized light, which is then focused. In addition, a horizontally aligned multifocal metalens can be achieved by designing reasonable phase and region distributions, which is similar to a vertically aligned one. Most significantly, a spatially 3D-arrayed multifocal metalens with low crosstalk is well achieved by combining these two distribution methods. The proposed bionic 3D-arrayed multifocal metalens with amazing focusing effect promises applications in imaging, nanoparticle manipulation, optical communication, and other fields. Full article
(This article belongs to the Special Issue Bionic Functional Interfaces and Devices for Low-Carbon Applications)
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Article
“Descriptive Risk-Averse Bayesian Decision-Making,” a Model for Complex Biological Motion Perception in the Human Dorsal Pathway
Biomimetics 2022, 7(4), 193; https://doi.org/10.3390/biomimetics7040193 - 07 Nov 2022
Viewed by 791
Abstract
Biological motion perception is integral not only to survival but also to the social life of human beings. Identifying the underlying mechanisms and their associated neurobiological substrates has been a matter of investigation and debate for some time. Although, in general, it is [...] Read more.
Biological motion perception is integral not only to survival but also to the social life of human beings. Identifying the underlying mechanisms and their associated neurobiological substrates has been a matter of investigation and debate for some time. Although, in general, it is believed that the integration of local motion and dynamic form cues in the brain empowers the visual system to perceive/recognize biological motion stimuli, some recent studies have indicated the importance of dynamic form cues in such a process. Inspired by the previous neurophysiologically plausible biological motion perception models, a new descriptive risk-averse Bayesian simulation model, capable of discerning a ball’s direction from a set of complex biological motion soccer kick stimuli, is proposed. The model represents only the dorsal pathway as a motion information processing section of the visual system according to the two-stream theory. The stimuli used have been obtained from a previous psychophysical study on athletes in our lab. Furthermore, the acquired psychophysical data from that study have been used to re-enact human behavior using our simulation model. By adjusting the model parameters, the psychometric function of athlete subjects has been mimicked. A correlation analysis between human and simulation data shows a significant and robust correlation between angular thresholds and slopes of the psychometric functions of both groups. Although it is established that the visual system optimally integrates all available information in the decision-making process, the results conform to the speculations favoring motion cue importance over dynamic form by testing the limits in which biological motion perception only depends on motion information processing. Full article
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Article
A Fast-Tracking-Particle-Inspired Flow-Aided Control Approach for Air Vehicles in Turbulent Flow
Biomimetics 2022, 7(4), 192; https://doi.org/10.3390/biomimetics7040192 - 06 Nov 2022
Viewed by 609
Abstract
Natural phenomena such as insect migration and the thermal soaring of birds in turbulent environments demonstrate animals’ abilities to exploit complex flow structures without knowledge of global velocity profiles. Similar energy-harvesting features can be observed in other natural phenomena such as particle transport [...] Read more.
Natural phenomena such as insect migration and the thermal soaring of birds in turbulent environments demonstrate animals’ abilities to exploit complex flow structures without knowledge of global velocity profiles. Similar energy-harvesting features can be observed in other natural phenomena such as particle transport in turbulent fluids. This paper presents a new feedback control approach inspired by experimental studies on particle transport that have recently illuminated particles’ ability to traverse homogeneous turbulence through the so-called fast-tracking effect. While in nature fast tracking is observed only in particles with inertial characteristics that match the flow parameters, the new fast-tracking feedback control approach presented in this paper employs available propulsion and actuation to allow the vehicle to respond to the surrounding flow in the same manner as ideal fast-tracking particles would. The resulting fast-tracking closed-loop controlled vehicle is then able to leverage homogeneous turbulent flow structures, such as sweeping eddies, to reduce travel time and energy consumption. The fast-tracking approach is shown to significantly outperform existing optimal control solutions, such as linear quadratic regulator and bang-bang control, and to be robust to changes in the vehicle characteristics and/or turbulent flow parameters. Full article
(This article belongs to the Special Issue Bio-Inspired Flight Systems and Bionic Aerodynamics)
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Article
Investigation on the Anisotropic Wetting Properties of Water Droplets on Bio-Inspired Groove Structures Fabricated by 3D Printing and Surface Modifications
Biomimetics 2022, 7(4), 174; https://doi.org/10.3390/biomimetics7040174 - 24 Oct 2022
Viewed by 573
Abstract
The self-driving structure to orientate the water movement has attracted considerable attention. Inspired by the wedgelike structures of biological materials in nature, such as spider silks and cactus spines, anisotropic spreading can be realized by combining Laplace pressure gradient and hydrophilic surface. In [...] Read more.
The self-driving structure to orientate the water movement has attracted considerable attention. Inspired by the wedgelike structures of biological materials in nature, such as spider silks and cactus spines, anisotropic spreading can be realized by combining Laplace pressure gradient and hydrophilic surface. In this study, a series of groove patterns were fabricated by a combination of 3D printing and surface modification. PLA pattern was modified by the atmospheric pressure plasma, followed by grafting with hydrolyzed APTES. This work reports the anisotropic transport of water droplets on a series of designed dart-shaped groove patterns with specific angles in the main arrow and tail regions. This structure can induce capillary force to regulate droplets from the main cone to two wedgelike, whereas the droplets are hindered toward the opposite side is oat the vicinity of the groove’s tail. By means of the experiment, the mechanism of water transport in this pattern was revealed. This study can contribute a potential approach to manipulate and apply anisotropic wetting in many fields. Full article
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Article
Convergent Evolution of Adhesive Properties in Leaf Insect Eggs and Plant Seeds: Cross-Kingdom Bioinspiration
Biomimetics 2022, 7(4), 173; https://doi.org/10.3390/biomimetics7040173 - 22 Oct 2022
Viewed by 744
Abstract
Plants and animals are often used as a source for inspiration in biomimetic engineering. However, stronger engagement of biologists is often required in the field of biomimetics. The actual strength of using biological systems as a source of inspiration for human problem solving [...] Read more.
Plants and animals are often used as a source for inspiration in biomimetic engineering. However, stronger engagement of biologists is often required in the field of biomimetics. The actual strength of using biological systems as a source of inspiration for human problem solving does not lie in a perfect copy of a single system but in the extraction of core principles from similarly functioning systems that have convergently solved the same problem in their evolution. Adhesive systems are an example of such convergent traits that independently evolved in different organisms. We herein compare two analogous adhesive systems, one from plants seeds and one from insect eggs, to test their properties and functional principles for differences and similarities in order to evaluate the input that can be potentially used for biomimetics. Although strikingly similar, the eggs of the leaf insect Phyllium philippinicum and the seeds of the ivy gourd Coccinia grandis make use of different surface structures for the generation of adhesion. Both employ a water-soluble glue that is spread on the surface via reinforcing fibrous surface structures, but the morphology of these structures is different. In addition to microscopic analysis of the two adhesive systems, we mechanically measured the actual adhesion generated by both systems to quantitatively compare their functional differences on various standardized substrates. We found that seeds can generate much stronger adhesion in some cases but overall provided less reliable adherence in comparison to eggs. Furthermore, eggs performed better regarding repetitive attachment. The similarities of these systems, and their differences resulting from their different purposes and different structural/chemical features, can be informative for engineers working on technical adhesive systems. Full article
(This article belongs to the Special Issue Biological Attachment Systems and Biomimetics)
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Article
Double-Acting Soft Actuator for Soft Robotic Hand: A Bellow Pumping and Contraction Approach
Biomimetics 2022, 7(4), 171; https://doi.org/10.3390/biomimetics7040171 - 20 Oct 2022
Viewed by 770
Abstract
When compressing a soft bellow, the bellow will contract and pump out the fluid inside the bellow. Utilizing this property, we propose a novel actuation method called compressing bellow actuation (CBA), which can output fluidic power and tendon-driven force simultaneously. Based on the [...] Read more.
When compressing a soft bellow, the bellow will contract and pump out the fluid inside the bellow. Utilizing this property, we propose a novel actuation method called compressing bellow actuation (CBA), which can output fluidic power and tendon-driven force simultaneously. Based on the CBA method, a double-acting soft actuator (DASA) combining fluidic elastomer actuator (FEA) and tendon-driven metacarpophalangeal (MCP) joint is proposed for robotic finger design. The proposed DASA exhibits both compliance and adaptiveness of FEAs, and controllability and large output force of the tendon-driven methods. The fluid in the bellow can be either air or water or even integration of the two, thus constituting three different actuation modes. Mathematical modeling of the relationship between bellow compression displacement and DASA’s bending angle is developed. Furthermore, experimental characterizations of DASA’s bending angle and blocking force are conducted at different actuation modes. The double-acting method can availably promote the bending angle of an FEA by up to 155%, and the blocking force by up to 132% when the FEA is water-filled. A soft robotic hand with a forearm prototype based on the DASA fingers is fabricated for the demonstration of finger motion and gripping applications. Full article
(This article belongs to the Special Issue Biomimetic Soft Robotics)
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Article
Injectability, Processability, Drug Loading, and Antibacterial Activity of Gentamicin-Impregnated Mesoporous Bioactive Glass Composite Calcium Phosphate Bone Cement In Vitro
Biomimetics 2022, 7(3), 121; https://doi.org/10.3390/biomimetics7030121 - 28 Aug 2022
Cited by 3 | Viewed by 1523
Abstract
Calcium phosphate cement (CPC) is similar to bone in composition and has plasticity, while mesoporous bioactive glass (MBG) has the advantage of releasing Si, which can promote osteogenic properties and drug loading capacity. A sol–gel-prepared MBG micro-powder (mMBG) and further impregnated antibiotic gentamicin [...] Read more.
Calcium phosphate cement (CPC) is similar to bone in composition and has plasticity, while mesoporous bioactive glass (MBG) has the advantage of releasing Si, which can promote osteogenic properties and drug loading capacity. A sol–gel-prepared MBG micro-powder (mMBG) and further impregnated antibiotic gentamicin sulfate ([email protected]: 2, 3, and 4 mg/mL) antibiotic were added to CPC at different weight ratios (5, 10, and 15 wt.%) to study CPC’s potential clinical applications. Different ratios of mMBG/CPC composite bone cement showed good injectability and disintegration resistance, but with increasing mMBG addition, the working/setting time and compressive strength decreased. The maximum additive amount was 10 wt.% mMBG due to the working time of ~5 min, the setting time of ~10 min, and the compressive strength of ~51 MPa, indicating that it was more suitable for clinical surgical applications than the other groups. The [email protected] group loaded with 2 mg/mL gentamicin had good antibacterial activity, and the 10 wt.% [email protected]/CPC composite bone cement still had good antibacterial activity but reduced the initial release of Genta. [email protected] was found to have slight cytotoxicity, so [email protected] was composited into CPC to improve the biocompatibility and to endow CPC with more advantages for clinical application. Full article
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Article
Novel Motion Sequences in Plant-Inspired Robotics: Combining Inspirations from Snap-Trapping in Two Plant Species into an Artificial Venus Flytrap Demonstrator
Biomimetics 2022, 7(3), 99; https://doi.org/10.3390/biomimetics7030099 - 22 Jul 2022
Cited by 1 | Viewed by 1450
Abstract
The field of plant-inspired robotics is based on principles underlying the movements and attachment and adaptability strategies of plants, which together with their materials systems serve as concept generators. The transference of the functions and underlying structural principles of plants thus enables the [...] Read more.
The field of plant-inspired robotics is based on principles underlying the movements and attachment and adaptability strategies of plants, which together with their materials systems serve as concept generators. The transference of the functions and underlying structural principles of plants thus enables the development of novel life-like technical materials systems. For example, principles involved in the hinge-less movements of carnivorous snap-trap plants and climbing plants can be used in technical applications. A combination of the snap-trap motion of two plant species (Aldrovanda vesiculosa and Dionaea muscipula) has led to the creation of a novel motion sequence for plant-inspired robotics in an artificial Venus flytrap system, the Venus Flyflap. The novel motion pattern of Venus Flyflap lobes has been characterized by using four state-of-the-art actuation systems. A kinematic analysis of the individual phases of the new motion cycle has been performed by utilizing precise pneumatic actuation. Contactless magnetic actuation augments lobe motion into energy-efficient resonance-like oscillatory motion. The use of environmentally driven actuator materials has allowed autonomous motion generation via changes in environmental conditions. Measurement of the energy required for the differently actuated movements has shown that the Venus Flyflap is not only faster than the biological models in its closing movement, but also requires less energy in certain cases for the execution of this movement. Full article
(This article belongs to the Special Issue Advances in Biomimetics)
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Article
Assessment of Optimal Conditions for Marine Invertebrate Cell-Mediated Mineralization of Organic Matrices
Biomimetics 2022, 7(3), 86; https://doi.org/10.3390/biomimetics7030086 - 26 Jun 2022
Viewed by 1428
Abstract
Cellular strategies and regulation of their crystallization mechanisms are essential to the formation of biominerals, and harnessing these strategies will be important for the future creation of novel non-native biominerals that recapitulate the impressive properties biominerals possess. Harnessing these biosynthetic strategies requires an [...] Read more.
Cellular strategies and regulation of their crystallization mechanisms are essential to the formation of biominerals, and harnessing these strategies will be important for the future creation of novel non-native biominerals that recapitulate the impressive properties biominerals possess. Harnessing these biosynthetic strategies requires an understanding of the interplay between insoluble organic matrices, mineral precursors, and soluble organic and inorganic additives. Our long-range goal is to use a sea anemone model system (Nematostella vectensis) to examine the role of intrinsically disordered proteins (IDPs) found in native biomineral systems. Here, we study how ambient temperatures (25–37 °C) and seawater solution compositions (varying NaCl and Mg ratios) will affect the infiltration of organic matrices with calcium carbonate mineral precursors generated through a polymer-induced liquid-precursor (PILP) process. Fibrillar collagen matrices were used to assess whether solution conditions were suitable for intrafibrillar mineralization, and SEM with EDS was used to analyze mineral infiltration. Conditions of temperatures 30 °C and above and with low Mg:Ca ratios were determined to be suitable conditions for calcium carbonate infiltration. The information obtained from these observations may be useful for the manipulation and study of cellular secreted IDPs in our quest to create novel biosynthetic materials. Full article
(This article belongs to the Special Issue Bioinspired Nanostructures for Innovative Functional Applications)
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Article
Preparation of a Novel Type of Zwitterionic Polymer and the Antifouling PDMS Coating
Biomimetics 2022, 7(2), 50; https://doi.org/10.3390/biomimetics7020050 - 21 Apr 2022
Viewed by 1884
Abstract
As awareness of environmental protection increases, environmentally friendly coatings have been receiving great interest. Zwitterionic polymers are considered promising candidates due to their biocompatibility and excellent antifouling properties. In this paper, a type of polypeptoid containing zwitterions on the side chain was synthesized [...] Read more.
As awareness of environmental protection increases, environmentally friendly coatings have been receiving great interest. Zwitterionic polymers are considered promising candidates due to their biocompatibility and excellent antifouling properties. In this paper, a type of polypeptoid containing zwitterions on the side chain was synthesized via ring-opening polymerization (ROP) and post-modification. This obtained polypeptoid was subsequently grafted onto the surface of polydimethylsiloxane (PDMS) via plasma and UV-induced surface polymerization. Surface morphology and protein adsorption tests of the resulting coating were systematically carried out. The results show that the modified coating has excellent antifouling properties and thus has great potential for environmentally friendly coating applications. Full article
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Communication
Bioinspired Photo-Responsive Liquid Gating Membrane
Biomimetics 2022, 7(2), 47; https://doi.org/10.3390/biomimetics7020047 - 18 Apr 2022
Cited by 4 | Viewed by 2149
Abstract
Stomata in the plant leaves are channels for gas exchange between the plants and the atmosphere. The gas exchange rate can be regulated by adjusting the opening and closing of stoma under the external stimuli, which plays a vital role in plant survival. [...] Read more.
Stomata in the plant leaves are channels for gas exchange between the plants and the atmosphere. The gas exchange rate can be regulated by adjusting the opening and closing of stoma under the external stimuli, which plays a vital role in plant survival. Under visible light irradiation, the stomata open for gas exchange with the surroundings, while under intense UV light irradiation, the stomata close to prevent the moisture loss of plants from excessive transpiration. Inspired by this stomatal self-protection behavior, we have constructed a bioinspired photo-responsive liquid gating membrane (BPRLGM) through infusing the photo-responsive gating liquid obtained by dissolving the azobenzene-based photo-responsive surfactant molecules (AzoC8F15) in N,N-Dimethylacetamide (DMAC) into nylon porous substrate, which can reversibly switch the open/closed states under different photo-stimuli. Theoretical analysis and experimental data have demonstrated that the reversible photoisomerization of azobenzene-based surfactant molecules induces a change in surface tension of the photo-responsive gating liquid, which eventually results in the reversible variation of substantial critical pressure for gas through BPRLGM under alternating UV (PCritical (off)) and visible (PCritical (on)) light irradiations. Therefore, driven by a pressure difference ΔP between PCritical (on) and PCritical (off), the reversible switches on the open/closed states of this photo-responsive liquid gating membrane can be realized under photo-stimuli. This bioinspired membrane with switchable open/closed liquid gating performance under photo-stimuli has the opportunity to be used in the precise and contactless control of microfluidics. Full article
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Article
Bio-Inspired Propulsion: Towards Understanding the Role of Pectoral Fin Kinematics in Manta-like Swimming
Biomimetics 2022, 7(2), 45; https://doi.org/10.3390/biomimetics7020045 - 15 Apr 2022
Cited by 10 | Viewed by 2739
Abstract
Through computational fluid dynamics (CFD) simulations of a model manta ray body, the hydrodynamic role of manta-like bioinspired flapping is investigated. The manta ray model motion is reconstructed from synchronized high-resolution videos of manta ray swimming. Rotation angles of the model skeletal joints [...] Read more.
Through computational fluid dynamics (CFD) simulations of a model manta ray body, the hydrodynamic role of manta-like bioinspired flapping is investigated. The manta ray model motion is reconstructed from synchronized high-resolution videos of manta ray swimming. Rotation angles of the model skeletal joints are altered to scale the pitching and bending, resulting in eight models with different pectoral fin pitching and bending ratios. Simulations are performed using an in-house developed immersed boundary method-based numerical solver. Pectoral fin pitching ratio (PR) is found to have significant implications in the thrust and efficiency of the manta model. This occurs due to more optimal vortex formation and shedding caused by the lower pitching ratio. Leading edge vortexes (LEVs) formed on the bottom of the fin, a characteristic of the higher PR cases, produced parasitic low pressure that hinders thrust force. Lowering the PR reduces the influence of this vortex while another LEV that forms on the top surface of the fin strengthens it. A moderately high bending ratio (BR) can slightly reduce power consumption. Finally, by combining a moderately high BR = 0.83 with PR = 0.67, further performance improvements can be made. This enhanced understanding of manta-inspired propulsive mechanics fills a gap in our understanding of the manta-like mobuliform locomotion. This motivates a new generation of manta-inspired robots that can mimic the high speed and efficiency of their biological counterpart. Full article
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Article
Recent Advances in Computational Modeling of Biomechanics and Biorheology of Red Blood Cells in Diabetes
Biomimetics 2022, 7(1), 15; https://doi.org/10.3390/biomimetics7010015 - 13 Jan 2022
Cited by 4 | Viewed by 2399
Abstract
Diabetes mellitus, a metabolic disease characterized by chronically elevated blood glucose levels, affects about 29 million Americans and more than 422 million adults all over the world. Particularly, type 2 diabetes mellitus (T2DM) accounts for 90–95% of the cases of vascular disease and [...] Read more.
Diabetes mellitus, a metabolic disease characterized by chronically elevated blood glucose levels, affects about 29 million Americans and more than 422 million adults all over the world. Particularly, type 2 diabetes mellitus (T2DM) accounts for 90–95% of the cases of vascular disease and its prevalence is increasing due to the rising obesity rates in modern societies. Although multiple factors associated with diabetes, such as reduced red blood cell (RBC) deformability, enhanced RBC aggregation and adhesion to the endothelium, as well as elevated blood viscosity are thought to contribute to the hemodynamic impairment and vascular occlusion, clinical or experimental studies cannot directly quantify the contributions of these factors to the abnormal hematology in T2DM. Recently, computational modeling has been employed to dissect the impacts of the aberrant biomechanics of diabetic RBCs and their adverse effects on microcirculation. In this review, we summarize the recent advances in the developments and applications of computational models in investigating the abnormal properties of diabetic blood from the cellular level to the vascular level. We expect that this review will motivate and steer the development of new models in this area and shift the attention of the community from conventional laboratory studies to combined experimental and computational investigations, aiming to provide new inspirations for the development of advanced tools to improve our understanding of the pathogenesis and pathology of T2DM. Full article
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Article
Structural Sizing and Topology Optimization Based on Weight Minimization of a Variable Tapered Span-Morphing Wing for Aerodynamic Performance Improvements
Biomimetics 2021, 6(4), 55; https://doi.org/10.3390/biomimetics6040055 - 26 Sep 2021
Cited by 1 | Viewed by 2983
Abstract
This article proposes the integration of structural sizing, topology, and aerodynamic optimization for a morphing variable span of tapered wing (MVSTW) with the aim to minimize its weight. In order to evaluate the feasibility of the morphing wing optimization, this work creates a [...] Read more.
This article proposes the integration of structural sizing, topology, and aerodynamic optimization for a morphing variable span of tapered wing (MVSTW) with the aim to minimize its weight. In order to evaluate the feasibility of the morphing wing optimization, this work creates a numerical environment by incorporating simultaneous structural sizing and topology optimization based on its aerodynamic analysis. This novel approach is proposed for an MVSTW. A problem-specific optimization approach to determine the minimum weight structure of the wing components for its fixed and moving segments is firstly presented. The optimization was performed using the OptiStruct solver inside HyperMesh. This investigation seeks to minimize total structure compliance while maximizing stiffness in order to satisfy the structural integrity requirements of the MVSTW. The aerodynamic load distribution along the wingspan at full wingspan extension and maximum speed were considered in the optimization processes. The wing components were optimized for size and topology, and all of them were built from aluminum alloy 2024-T3. The optimization results show that weight savings of up to 51.2% and 55.7% were obtained for fixed and moving wing segments, respectively. Based on these results, the optimized variable-span morphing wing can perform certain flight missions perfectly without experiencing any mechanical failures. Full article
(This article belongs to the Special Issue Aircraft Morphing Systems 2.0)
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Article
New Aerodynamic Studies of an Adaptive Winglet Application on the Regional Jet CRJ700
Biomimetics 2021, 6(4), 54; https://doi.org/10.3390/biomimetics6040054 - 24 Sep 2021
Cited by 5 | Viewed by 2695
Abstract
This study aims to evaluates how an adaptive winglet during flight can improve aircraft aerodynamic characteristics of the CRJ700. The aircraft geometry was slightly modified to integrate a one-rotation axis adaptive winglet. Aerodynamic characteristics of the new adaptive design were computed using a [...] Read more.
This study aims to evaluates how an adaptive winglet during flight can improve aircraft aerodynamic characteristics of the CRJ700. The aircraft geometry was slightly modified to integrate a one-rotation axis adaptive winglet. Aerodynamic characteristics of the new adaptive design were computed using a validated high-fidelity aerodynamic model developed with the open-source code OpenFoam. The aerodynamic model successively uses the two solvers simpleFoam and rhoSimpleFoam based on Reynold Averaged Navier Stokes equations. Characteristics of the adaptive winglet design were studied for 16 flight conditions, representative of climb and cruise usually considered by the CRJ700. The adaptive winglet can increase the lift-to-drag ratio by up to 6.10% and reduce the drag coefficient by up to 2.65%. This study also compared the aerodynamic polar and pitching moment coefficients variations of the Bombardier CRJ700 equipped with an adaptive versus a fixed winglet. Full article
(This article belongs to the Special Issue Aircraft Morphing Systems 2.0)
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Article
Biomimetics and Education in Europe: Challenges, Opportunities, and Variety
Biomimetics 2021, 6(3), 49; https://doi.org/10.3390/biomimetics6030049 - 04 Aug 2021
Cited by 8 | Viewed by 3775
Abstract
Biomimetics is an interdisciplinary field of science that deals with the analysis and systematic transfer of biological insights into technical applications. Moreover, the development of biomimetic products helps to improve our understanding of biological concept generators (reverse biomimetics). What does this mean for [...] Read more.
Biomimetics is an interdisciplinary field of science that deals with the analysis and systematic transfer of biological insights into technical applications. Moreover, the development of biomimetic products helps to improve our understanding of biological concept generators (reverse biomimetics). What does this mean for the education of kindergarten children, pupils, students, teachers, and others interested in biomimetics? The challenge of biomimetics is to have a solid knowledge base in the scientific disciplines involved and the competency to be open-minded enough to develop innovative solutions. This apparently contradictory combination ensures the transfer of knowledge from biology to engineering and vice versa on the basis of a common language that is perfectly understandable to everyone, e.g., the language of models, algorithms, and complete mathematical formulations. The opportunity within biomimetics is its ability to arouse student interest in technology via the fascination inherent in biological solutions and to awaken enthusiasm for living nature via the understanding of technology. Collaboration in working groups promotes professional, social, and personal skills. The variety of biomimetics is mirrored by the large number of educational modules developed with respect to existing biomimetic products and methods. Full article
(This article belongs to the Special Issue Biomimetic Process and Pedagogy)
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Article
Self-Actuated Paper and Wood Models: Low-Cost Handcrafted Biomimetic Compliant Systems for Research and Teaching
Biomimetics 2021, 6(3), 42; https://doi.org/10.3390/biomimetics6030042 - 22 Jun 2021
Cited by 5 | Viewed by 3033
Abstract
The abstraction and implementation of plant movement principles into biomimetic compliant systems are of increasing interest for technical applications, e.g., in architecture, medicine, and soft robotics. Within the respective research and development approaches, advanced methods such as 4D printing or 3D-braiding pultrusion are [...] Read more.
The abstraction and implementation of plant movement principles into biomimetic compliant systems are of increasing interest for technical applications, e.g., in architecture, medicine, and soft robotics. Within the respective research and development approaches, advanced methods such as 4D printing or 3D-braiding pultrusion are typically used to generate proof-of-concept demonstrators at the laboratory or demonstrator scale. However, such techniques are generally time-consuming, complicated, and cost-intensive, which often impede the rapid realization of a sufficient number of demonstrators for testing or teaching. Therefore, we have produced comparable simple handcrafted compliant systems based on paper, wood, plastic foil, and/or glue as construction materials. A variety of complex plant movement principles have been transferred into these low-cost physical demonstrators, which are self-actuated by shrinking processes induced by the anisotropic hygroscopic properties of wood or paper. The developed systems have a high potential for fast, precise, and low-cost abstraction and transfer processes in biomimetic approaches and for the “hands-on understanding” of plant movements in applied university and school courses. Full article
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Article
Design of a Depth Control Mechanism for an Anguilliform Swimming Robot
Biomimetics 2021, 6(2), 39; https://doi.org/10.3390/biomimetics6020039 - 09 Jun 2021
Viewed by 2684
Abstract
This paper discusses the design and implementation of a depth control mechanism for an anguilliform swimming robot. Researchers analyzed three different methods of controlling the depth of the robot, including out-of-plane thrust direction, use of foil on the head and buoyancy control at [...] Read more.
This paper discusses the design and implementation of a depth control mechanism for an anguilliform swimming robot. Researchers analyzed three different methods of controlling the depth of the robot, including out-of-plane thrust direction, use of foil on the head and buoyancy control at the head and tail. It was determined that buoyancy control at the head and tail was the best method for controlling depth and pitch, given typical forward speeds of the robot. Details are given into the design of this mechanism, including a stress analysis on a critical part, as well as the impacts that these modifications have on the required torque of the drive servos. Full article
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Article
Textured Building Façades: Utilizing Morphological Adaptations Found in Nature for Evaporative Cooling
Biomimetics 2021, 6(2), 24; https://doi.org/10.3390/biomimetics6020024 - 29 Mar 2021
Cited by 6 | Viewed by 3500
Abstract
The overheating of buildings and their need for mechanical cooling is a growing issue as a result of climate change. The main aim of this paper is to examine the impact of surface texture on heat loss capabilities of concrete panels through evaporative [...] Read more.
The overheating of buildings and their need for mechanical cooling is a growing issue as a result of climate change. The main aim of this paper is to examine the impact of surface texture on heat loss capabilities of concrete panels through evaporative cooling. Organisms maintain their body temperature in very narrow ranges in order to survive, where they employ morphological and behavioral means to complement physiological strategies for adaptation. This research follows a biomimetic approach to develop a design solution. The skin morphology of elephants was identified as a successful example that utilizes evaporative cooling and has, therefore, informed the realization of a textured façade panel. A systematic process has been undertaken to examine the impact of different variables on the cooling ability of the panels, bringing in new morphological considerations for surface texture. The results showed that the morphological variables of assembly and depth of texture have impact on heat loss, and the impact of surface area to volume (SA:V) ratios on heat loss capabilities varies for different surface roughness. This study demonstrates the potential exploitation of morphological adaptation to buildings, that could contribute to them cooling passively and reduce the need for expensive and energy consuming mechanical systems. Furthermore, it suggests areas for further investigation and opens new avenues for novel thermal solutions inspired by nature for the built environment. Full article
(This article belongs to the Special Issue Biomimetic Architectural and Urban Design)
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Article
Bio-Inspired Design of a Porous Resorbable Scaffold for Bone Reconstruction: A Preliminary Study
Biomimetics 2021, 6(1), 18; https://doi.org/10.3390/biomimetics6010018 - 10 Mar 2021
Cited by 18 | Viewed by 2591
Abstract
The study and imitation of the biological and mechanical systems present in nature and living beings always have been sources of inspiration for improving existent technologies and establishing new ones. Pursuing this line of thought, we consider an artificial graft typical in the [...] Read more.
The study and imitation of the biological and mechanical systems present in nature and living beings always have been sources of inspiration for improving existent technologies and establishing new ones. Pursuing this line of thought, we consider an artificial graft typical in the bone reconstruction surgery with the same microstructure of the bone living tissue and examine the interaction between these two phases, namely bone and the graft material. Specifically, a visco-poroelastic second gradient model is adopted for the bone-graft composite system to describe it at a macroscopic level of observation. The second gradient formulation is employed to consider possibly size effects and as a macroscopic source of interstitial fluid flow, which is usually regarded as a key factor in bone remodeling. With the help of the proposed formulation and via a simple example, we show that the model can be used as a graft design tool. As a matter of fact, an optimization of the characteristics of the implant can be carried out by numerical investigations. In this paper, we observe that the size of the graft considerably influences the interaction between bone tissue and artificial bio-resorbable material and the possibility that the bone tissue might substitute more or less partially the foreign graft for better bone healing. Full article
(This article belongs to the Special Issue Bioinspired Intelligence II)
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