Biomimetics

20 pages, 2415 KiB

Open AccessArticle

Implementation of Deep Deterministic Policy Gradients for Controlling Dynamic Bipedal Walking

by Chujun Liu, Andrew G. Lonsberry, Mark J. Nandor, Musa L. Audu, Alexander J. Lonsberry and Roger D. Quinn

Biomimetics 2019, 4(1), 28; https://doi.org/10.3390/biomimetics4010028 - 22 Mar 2019

Cited by 11 | Viewed by 3530

Abstract

A control system for bipedal walking in the sagittal plane was developed in simulation. The biped model was built based on anthropometric data for a 1.8 m tall male of average build. At the core of the controller is a deep deterministic policy [...] Read more.

A control system for bipedal walking in the sagittal plane was developed in simulation. The biped model was built based on anthropometric data for a 1.8 m tall male of average build. At the core of the controller is a deep deterministic policy gradient (DDPG) neural network that was trained in GAZEBO, a physics simulator, to predict the ideal foot placement to maintain stable walking despite external disturbances. The complexity of the DDPG network was decreased through carefully selected state variables and a distributed control system. Additional controllers for the hip joints during their stance phases and the ankle joint during toe-off phase help to stabilize the biped during walking. The simulated biped can walk at a steady pace of approximately 1 m/s, and during locomotion it can maintain stability with a 30 kg·m/s impulse applied forward on the torso or a 40 kg·m/s impulse applied rearward. It also maintains stable walking with a 10 kg backpack or a 25 kg front pack. The controller was trained on a 1.8 m tall model, but also stabilizes models 1.4–2.3 m tall with no changes. Full article

(This article belongs to the Special Issue Selected Papers from Living Machines 2018)

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21 pages, 12797 KiB

Open AccessArticle

Fluid–Structure Interaction for Biomimetic Design of an Innovative Lightweight Turboexpander

by Ibrahim Gad-el-Hak

Biomimetics 2019, 4(1), 27; https://doi.org/10.3390/biomimetics4010027 - 22 Mar 2019

Cited by 6 | Viewed by 5432

Abstract

Inspired by bird feather structures that enable the resistance of powerful aerodynamic forces in addition to their lower weight to provide stable flight, a biomimetic composite turbine blade was proposed for a low-temperature organic Rankine cycle (ORC) turboexpander that is capable of producing [...] Read more.

Inspired by bird feather structures that enable the resistance of powerful aerodynamic forces in addition to their lower weight to provide stable flight, a biomimetic composite turbine blade was proposed for a low-temperature organic Rankine cycle (ORC) turboexpander that is capable of producing lower weight expanders than that of stainless steel expanders, in addition to reduce its manufacturing cost, and hence it may contribute in spreading ORC across nonconventional power systems. For that purpose, the fluid–structure interaction (FSI) was numerically investigated for a composite turbine blade with bird-inspired fiber orientations. The aerodynamic forces were evaluated by computational fluid dynamics (CFD) using the commercial package ANSYS-CFX (version 16.0) and then these aerodynamic forces were transferred to the solid model of the proposed blade. The structural integrity of the bird-mimetic composite blade was investigated by performing finite element analysis (FEA) of composite materials with different fiber orientations using ANSYS Composite PrepPost (ACP). Furthermore, the obtained mechanical performance of the composite turbine blades was compared with that of the stainless steel turbine blades. The obtained results indicated that fiber orientation has a greater effect on the deformation of the rotor blades and the minimum value can be achieved by the same barb angle inspired from the flight feather. In addition to a significant effect in the weight reduction of 80% was obtained by using composite rotor blades instead of stainless steel rotor blades. Full article

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34 pages, 8762 KiB

Open AccessReview

An Overview of Bioinspired and Biomimetic Self-Repairing Materials

by Olga Speck and Thomas Speck

Biomimetics 2019, 4(1), 26; https://doi.org/10.3390/biomimetics4010026 - 20 Mar 2019

Cited by 83 | Viewed by 13593

Abstract

During the 3.8 billion years of biological evolution, a multitude of functional principles has been developed in all kingdoms of life enabling the sealing and healing of diverse types of damage. Inspired by this treasure trove, biologists and engineers have become increasingly interested [...] Read more.

During the 3.8 billion years of biological evolution, a multitude of functional principles has been developed in all kingdoms of life enabling the sealing and healing of diverse types of damage. Inspired by this treasure trove, biologists and engineers have become increasingly interested in learning from biological insights for the development of self-repairing materials. In this review, particular attention is paid to the systematic transfer of knowledge from wound reactions in biological role models to technical applications with self-repair function. This knowledge transfer includes bioinspiration in terms of the conscious implementation of an idea from nature or biomimetics in the form of a systematic transfer of underlying functional principles found in selected biological role models. The current overview presents a selection of breakthroughs regarding bioinspired or biomimetic self-repairing materials, including the initial basic publications and the recent publications of the last eight years. Each reviewed publication is presented with reference to three key criteria: (i) self-repair mechanisms in plants or animals as role models; (ii) knowledge transfer from living nature to technology; and (iii) bioinspired or biomimetic materials with self-repair function. Finally, damage control is discussed with a focus on damage prevention and damage management. Full article

(This article belongs to the Special Issue Biogenic and Bioinspired Self-Healing Materials)

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17 pages, 2528 KiB

Open AccessArticle

Bioinspired Histidine–Zn²⁺ Coordination for Tuning the Mechanical Properties of Self-Healing Coiled Coil Cross-Linked Hydrogels

by Isabell Tunn, Matthew J. Harrington and Kerstin G. Blank

Biomimetics 2019, 4(1), 25; https://doi.org/10.3390/biomimetics4010025 - 18 Mar 2019

Cited by 40 | Viewed by 6184

Abstract

Natural biopolymeric materials often possess properties superior to their individual components. In mussel byssus, reversible histidine (His)–metal coordination is a key feature, which mediates higher-order self-assembly as well as self-healing. The byssus structure, thus, serves as an excellent natural blueprint for the development [...] Read more.

Natural biopolymeric materials often possess properties superior to their individual components. In mussel byssus, reversible histidine (His)–metal coordination is a key feature, which mediates higher-order self-assembly as well as self-healing. The byssus structure, thus, serves as an excellent natural blueprint for the development of self-healing biomimetic materials with reversibly tunable mechanical properties. Inspired by byssal threads, we bioengineered His–metal coordination sites into a heterodimeric coiled coil (CC). These CC-forming peptides serve as a noncovalent cross-link for poly(ethylene glycol)-based hydrogels and participate in the formation of higher-order assemblies via intermolecular His–metal coordination as a second cross-linking mode. Raman and circular dichroism spectroscopy revealed the presence of α-helical, Zn²⁺ cross-linked aggregates. Using rheology, we demonstrate that the hydrogel is self-healing and that the addition of Zn²⁺ reversibly switches the hydrogel properties from viscoelastic to elastic. Importantly, using different Zn²⁺:His ratios allows for tuning the hydrogel relaxation time over nearly three orders of magnitude. This tunability is attributed to the progressive transformation of single CC cross-links into Zn²⁺ cross-linked aggregates; a process that is fully reversible upon addition of the metal chelator ethylenediaminetetraacetic acid. These findings reveal that His–metal coordination can be used as a versatile cross-linking mechanism for tuning the viscoelastic properties of biomimetic hydrogels. Full article

(This article belongs to the Special Issue Biogenic and Bioinspired Self-Healing Materials)

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18 pages, 2338 KiB

Open AccessArticle

Synthesis and Mechanochemical Activity of Peptide-Based Cu(I) Bis(N-heterocyclic carbene) Complexes

by Sebastian Funtan, Philipp Michael and Wolfgang H. Binder

Biomimetics 2019, 4(1), 24; https://doi.org/10.3390/biomimetics4010024 - 14 Mar 2019

Cited by 19 | Viewed by 4883

Abstract

With the class of shock-absorbing proteins, nature created some of the most robust materials combining both mechanical strength and elasticity. Their excellent ability to dissipate energy to prevent surrounding cells from damage is an interesting property that regularly is exploited for applications in [...] Read more.

With the class of shock-absorbing proteins, nature created some of the most robust materials combining both mechanical strength and elasticity. Their excellent ability to dissipate energy to prevent surrounding cells from damage is an interesting property that regularly is exploited for applications in biomimetic materials. Similar to biomaterials, where mechanical stimuli are transmitted into a (bio)chemical response, mechanophoric catalysts transform mechanical energy into a chemical reaction. Force transmission is realized commonly by polymeric handles directing the applied force to the mechanophoric bond, which in turn leads to stress-induced activation of the catalyst. Therefore, shock-absorbing proteins able to take up and store mechanical energy elastically for subsequent force transduction to the labile bond seem to be perfect candidates to fulfill this task. Here, we report on the synthesis of two different latent mechanophoric copper(I) bis(N-heterocyclic carbene) complexes bearing either two carboxyl groups or two amino groups which allow conjugation reactions with either the N- or the C-terminus of amino acids or peptides. The chosen catalysts can be activated, for instance, by applying external mechanical force via ultrasound, removing one N-heterocyclic carbene (NHC) ligand. Post-modification of the mechanophoric catalysts via peptide coupling (Gly, Val) and first reactions showed that the mechanoresponsive behavior was still present after the coupling. Subsequent polycondensation of both catalysts lead to a polyamide including the Cu(I) moiety. Mechanochemical activation by ultrasound showed conversions in the copper(I)-catalyzed alkyne-azide “click” reaction (CuAAC) up to 9.9% proving the potential application for the time and spatial controlled CuAAC. Full article

(This article belongs to the Special Issue Biogenic and Bioinspired Self-Healing Materials)

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22 pages, 6618 KiB

Open AccessArticle

Passing the Wake: Using Multiple Fins to Shape Forces for Swimming

by Anthony P. Mignano, Shraman Kadapa, James L. Tangorra and George V. Lauder

Biomimetics 2019, 4(1), 23; https://doi.org/10.3390/biomimetics4010023 - 12 Mar 2019

Cited by 39 | Viewed by 5189

Abstract

Fish use coordinated motions of multiple fins and their body to swim and maneuver underwater with more agility than contemporary unmanned underwater vehicles (UUVs). The location, utilization and kinematics of fins vary for different locomotory tasks and fish species. The relative position and [...] Read more.

Fish use coordinated motions of multiple fins and their body to swim and maneuver underwater with more agility than contemporary unmanned underwater vehicles (UUVs). The location, utilization and kinematics of fins vary for different locomotory tasks and fish species. The relative position and timing (phase) of fins affects how the downstream fins interact with the wake shed by the upstream fins and body, and change the magnitude and temporal profile of the net force vector. A multifin biorobotic experimental platform and a two-dimensional computational fluid dynamic simulation were used to understand how the propulsive forces produced by multiple fins were affected by the phase and geometric relationships between them. This investigation has revealed that forces produced by interacting fins are very different from the vector sum of forces from combinations of noninteracting fins, and that manipulating the phase and location of multiple interacting fins greatly affect the magnitude and shape of the produced propulsive forces. The changes in net forces are due, in large part, to time-varying wakes from dorsal and anal fins altering the flow experienced by the downstream body and caudal fin. These findings represent a potentially powerful means of manipulating the swimming forces produced by multifinned robotic systems. Full article

(This article belongs to the Special Issue Fluid Dynamic Interactions in Biological and Bioinspired Propulsion)

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3 pages, 144 KiB

Open AccessEditorial

Soft Robotics

by Barbara Mazzolai

Biomimetics 2019, 4(1), 22; https://doi.org/10.3390/biomimetics4010022 - 12 Mar 2019

Cited by 2 | Viewed by 2932

Abstract

In Nature, the adaptability of many organisms and their capability to survive in challenging and dynamically changing environments are closely linked to their characteristics and the morphology of their body parts [...] Full article

(This article belongs to the Special Issue Soft Robotics)

19 pages, 7190 KiB

Open AccessArticle

Neuromechanical Model of Rat Hindlimb Walking with Two-Layer CPGs

by Kaiyu Deng, Nicholas S. Szczecinski, Dirk Arnold, Emanuel Andrada, Martin S. Fischer, Roger D. Quinn and Alexander J. Hunt

Biomimetics 2019, 4(1), 21; https://doi.org/10.3390/biomimetics4010021 - 01 Mar 2019

Cited by 15 | Viewed by 4817

Abstract

This work demonstrates a neuromechanical model of rat hindlimb locomotion undergoing nominal walking with perturbations. In the animal, two types of responses to perturbations are observed: resetting and non-resetting deletions. This suggests that the animal locomotor system contains a memory-like organization. To model [...] Read more.

This work demonstrates a neuromechanical model of rat hindlimb locomotion undergoing nominal walking with perturbations. In the animal, two types of responses to perturbations are observed: resetting and non-resetting deletions. This suggests that the animal locomotor system contains a memory-like organization. To model this phenomenon, we built a synthetic nervous system that uses separate rhythm generator and pattern formation layers to activate antagonistic muscle pairs about each joint in the sagittal plane. Our model replicates the resetting and non-resetting deletions observed in the animal. In addition, in the intact (i.e., fully afferented) rat walking simulation, we observe slower recovery after perturbation, which is different from the deafferented animal experiment. These results demonstrate that our model is a biologically feasible description of some of the neural circuits in the mammalian spinal cord that control locomotion, and the difference between our simulation and fictive motion shows the importance of sensory feedback on motor output. This model also demonstrates how the pattern formation network can activate muscle synergies in a coordinated way to produce stable walking, which motivates the use of more complex synergies activating more muscles in the legs for three-dimensional limb motion. Full article

(This article belongs to the Special Issue Selected Papers from Living Machines 2018)

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21 pages, 7110 KiB

Open AccessReview

Healing through Histidine: Bioinspired Pathways to Self-Healing Polymers via Imidazole–Metal Coordination

by Stefan Zechel, Martin D. Hager, Tobias Priemel and Matthew J. Harrington

Biomimetics 2019, 4(1), 20; https://doi.org/10.3390/biomimetics4010020 - 27 Feb 2019

Cited by 61 | Viewed by 15234

Abstract

Biology offers a valuable inspiration toward the development of self-healing engineering composites and polymers. In particular, chemical level design principles extracted from proteinaceous biopolymers, especially the mussel byssus, provide inspiration for design of autonomous and intrinsic healing in synthetic polymers. The mussel byssus [...] Read more.

Biology offers a valuable inspiration toward the development of self-healing engineering composites and polymers. In particular, chemical level design principles extracted from proteinaceous biopolymers, especially the mussel byssus, provide inspiration for design of autonomous and intrinsic healing in synthetic polymers. The mussel byssus is an acellular tissue comprised of extremely tough protein-based fibers, produced by mussels to secure attachment on rocky surfaces. Threads exhibit self-healing response following an apparent plastic yield event, recovering initial material properties in a time-dependent fashion. Recent biochemical analysis of the structure–function relationships defining this response reveal a key role of sacrificial cross-links based on metal coordination bonds between Zn²⁺ ions and histidine amino acid residues. Inspired by this example, many research groups have developed self-healing polymeric materials based on histidine (imidazole)–metal chemistry. In this review, we provide a detailed overview of the current understanding of the self-healing mechanism in byssal threads, and an overview of the current state of the art in histidine- and imidazole-based synthetic polymers. Full article

(This article belongs to the Special Issue Biogenic and Bioinspired Self-Healing Materials)

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17 pages, 7758 KiB

Open AccessArticle

Cellulose Nanofiber-Reinforced Chitosan Hydrogel Composites for Intervertebral Disc Tissue Repair

by Ingo Doench, Tuan Ahn Tran, Laurent David, Alexandra Montembault, Eric Viguier, Christian Gorzelanny, Guillaume Sudre, Thibaut Cachon, Malika Louback-Mohamed, Niels Horbelt, Carlos Peniche-Covas and Anayancy Osorio-Madrazo

Biomimetics 2019, 4(1), 19; https://doi.org/10.3390/biomimetics4010019 - 20 Feb 2019

Cited by 71 | Viewed by 7505

Abstract

The development of non-cellularized composites of chitosan (CHI) hydrogels, filled with cellulose nanofibers (CNFs) of the type nanofibrillated cellulose, was proposed for the repair and regeneration of the intervertebral disc (IVD) annulus fibrosus (AF) tissue. With the achievement of CNF-filled CHI hydrogels, biomaterial-based [...] Read more.

The development of non-cellularized composites of chitosan (CHI) hydrogels, filled with cellulose nanofibers (CNFs) of the type nanofibrillated cellulose, was proposed for the repair and regeneration of the intervertebral disc (IVD) annulus fibrosus (AF) tissue. With the achievement of CNF-filled CHI hydrogels, biomaterial-based implants were designed to restore damaged/degenerated discs. The structural, mechanical and biological properties of the developed hydrogel composites were investigated. The neutralization of weakly acidic aqueous CNF/CHI viscous suspensions in NaOH yielded composites of physical hydrogels in which the cellulose nanofibers reinforced the CHI matrix, as investigated by means of microtensile testing under controlled humidity. We assessed the suitability of the achieved biomaterials for intervertebral disc tissue engineering in ex vivo experiments using spine pig models. Cellulose nanofiber-filled chitosan hydrogels can be used as implants in AF tissue defects to restore IVD biomechanics and constitute contention patches against disc nucleus protrusion while serving as support for IVD regeneration. Full article

(This article belongs to the Special Issue Chitin- and Chitosan-Based Composite Materials)

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9 pages, 782 KiB

Open AccessArticle

Synthesis of Optimized Molecularly Imprinted Polymers for the Isolation and Detection of Antidepressants via HPLC

by Alexander D. Hudson, Ricard Solà, Jorge T. Ueta, William Battell, Oliver Jamieson, Thomas Dunbar, Beatriz Maciá and Marloes Peeters

Biomimetics 2019, 4(1), 18; https://doi.org/10.3390/biomimetics4010018 - 20 Feb 2019

Cited by 8 | Viewed by 3822

Abstract

Antidepressants such as amitryptiline and fluoxetine are on the list of modern essential medicines of the World Health Organization. However, there are growing concerns regarding the ecological impact of these pharmaceuticals, leading to a great need to improve current wastewater treatment procedures. In [...] Read more.

Antidepressants such as amitryptiline and fluoxetine are on the list of modern essential medicines of the World Health Organization. However, there are growing concerns regarding the ecological impact of these pharmaceuticals, leading to a great need to improve current wastewater treatment procedures. In this contribution, we will report on the use of molecularly imprinted polymers (MIPs) for the extraction of antidepressants in water samples. MIPs were developed for fluoxetine and duloxetine, antidepressants belonging to the class of selective serotonin reuptake inhibitors (SSRIs). The binding capacity of these microparticles was evaluated using ultraviolet–visible (UV–Vis) spectroscopy. A new high-performance liquid chromatography (HPLC) procedure coupled to UV detection was developed, which enabled the study of mixtures of fluoxetine and duloxetine with other nitrogen-containing compounds. These results indicate that it is possible to selectively extract SSRIs from complex samples. Therefore, these versatile polymers are a promising analytical tool for the clean-up of water samples, which will benefit aquatic life and reduce the ecological impact of pharmaceuticals. Full article

(This article belongs to the Special Issue Selected Papers from Bioinspired Materials 2018)

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12 pages, 1651 KiB

Open AccessArticle

Effects of Capsaicin on Biomimetic Membranes

by Neha Sharma, Huong T. T. Phan, Tsuyoshi Yoda, Naofumi Shimokawa, Mun’delanji C. Vestergaard and Masahiro Takagi

Biomimetics 2019, 4(1), 17; https://doi.org/10.3390/biomimetics4010017 - 13 Feb 2019

Cited by 25 | Viewed by 4823

Abstract

Capsaicin is a natural compound that produces a warm sensation and is known for its remarkable medicinal properties. Understanding the interaction between capsaicin with lipid membranes is essential to clarify the molecular mechanisms behind its pharmacological and biological effects. In this study, we [...] Read more.

Capsaicin is a natural compound that produces a warm sensation and is known for its remarkable medicinal properties. Understanding the interaction between capsaicin with lipid membranes is essential to clarify the molecular mechanisms behind its pharmacological and biological effects. In this study, we investigated the effect of capsaicin on thermoresponsiveness, fluidity, and phase separation of liposomal membranes. Liposomal membranes are a bioinspired technology that can be exploited to understand biological mechanisms. We have shown that by increasing thermo-induced membrane excess area, capsaicin promoted membrane fluctuation. The effect of capsaicin on membrane fluidity was dependent on lipid composition. Capsaicin increased fluidity of (1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) membranes, while it rigidified DOPC and cholesterol-based liposomes. In addition, capsaicin tended to decrease phase separation of heterogeneous liposomes, inducing homogeneity. We imagine this lipid re-organization to be associated with the physiological warming sensation upon consumption of capsaicin. Since capsaicin has been reported to have biological properties such as antimicrobial and as antiplatelet, the results will help unravel these biological properties. Full article

(This article belongs to the Special Issue Selected Papers from Bioinspired Materials 2018)

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8 pages, 2145 KiB

Open AccessReview

Bioinspiration in Fashion—A Review

by Jane Wood

Biomimetics 2019, 4(1), 16; https://doi.org/10.3390/biomimetics4010016 - 12 Feb 2019

Cited by 23 | Viewed by 12282

Abstract

This paper provides an overview of the main technologies currently being investigated in the textile industry as alternatives to contemporary fashion fabrics. The present status of the textile industry and its impact on the environment is discussed, and the key drivers for change [...] Read more.

This paper provides an overview of the main technologies currently being investigated in the textile industry as alternatives to contemporary fashion fabrics. The present status of the textile industry and its impact on the environment is discussed, and the key drivers for change are highlighted. Historical use of bioinspiration in synthetic textiles is evaluated, with the impact of these developments on the fashion and apparel industries described. The review then discusses the move to nature as a supplier of new fabric sources with several alternatives explored, drawing special attention to the sustainability and performance aspects of these new sources. Full article

(This article belongs to the Special Issue Selected Papers from Bioinspired Materials 2018)

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16 pages, 5882 KiB

Open AccessArticle

Synthesis and Characterization of Acetic Acid-Doped Polyaniline and Polyaniline–Chitosan Composite

by Bianca Rae Pasela, Acelle Pearl Castillo, Rhenish Simon, Maria Teresa Pulido, Haidee Mana-ay, Ma. Roxan Abiquibil, Rhys Montecillo, Kanjana Thumanu, Doebner von Tumacder and Kathrina Lois Taaca

Biomimetics 2019, 4(1), 15; https://doi.org/10.3390/biomimetics4010015 - 11 Feb 2019

Cited by 28 | Viewed by 5343

Abstract

Polyaniline–chitosan (PAni–Cs) composite films were synthesized using a solution casting method with varying PAni concentrations. Polyaniline powders used in the composite synthesis were polymerized using acetic acid as the dopant media. Raman spectroscopy revealed that the PAni powders synthesized using hydrochloric acid and [...] Read more.

Polyaniline–chitosan (PAni–Cs) composite films were synthesized using a solution casting method with varying PAni concentrations. Polyaniline powders used in the composite synthesis were polymerized using acetic acid as the dopant media. Raman spectroscopy revealed that the PAni powders synthesized using hydrochloric acid and acetic acid did not exhibit significant difference to the chemical features of PAni, implying that PAni was formed in varying concentrations of the dopant media. The presence of agglomerated particles on the surface of the Cs composite, which may have been due to the presence of PAni powders, was observed with scanning electron microscope–energy dispersive X-ray spectroscopy (SEM–EDX). Ultraviolet–visible (UV–Vis) spectroscopy further showed the interaction of PAni with Cs where the Cs characteristic peak shifted to a higher wavelength. Cell viability assay also revealed that the synthesized PAni–Cs composites were nontoxic and may be utilized for future biomedical applications. Full article

(This article belongs to the Special Issue Chitin- and Chitosan-Based Composite Materials)

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1 pages, 179 KiB

Open AccessErratum

Erratum: 1st Symposium on Polydopamine and NanoTech Poland 2018: Conference Report. Biomimetics 2018, 3, 37

by Radosław Mrówczyński, Marco d’Ischia, Haeshin Lee and Stefan Jurga

Biomimetics 2019, 4(1), 14; https://doi.org/10.3390/biomimetics4010014 - 07 Feb 2019

Cited by 1 | Viewed by 2208

Abstract

The authors regret that few mistakes were made in the original publication by Mrówczyński et al [...] Full article

(This article belongs to the Special Issue Selected Papers from NanoTech Poland 2018 and 1st Symposium on Polydopamine)

16 pages, 3725 KiB

Open AccessArticle

Design and Actuation of a Fabric-Based Worm-Like Robot

by Akhil Kandhari, Anna Mehringer, Hillel J. Chiel, Roger D. Quinn and Kathryn A. Daltorio

Biomimetics 2019, 4(1), 13; https://doi.org/10.3390/biomimetics4010013 - 06 Feb 2019

Cited by 17 | Viewed by 5565

Abstract

Soft-bodied animals, such as earthworms, are capable of contorting their body to squeeze through narrow spaces, create or enlarge burrows, and move on uneven ground. In many applications such as search and rescue, inspection of pipes and medical procedures, it may be useful [...] Read more.

Soft-bodied animals, such as earthworms, are capable of contorting their body to squeeze through narrow spaces, create or enlarge burrows, and move on uneven ground. In many applications such as search and rescue, inspection of pipes and medical procedures, it may be useful to have a hollow-bodied robot with skin separating inside and outside. Textiles can be key to such skins. Inspired by earthworms, we developed two new robots: FabricWorm and MiniFabricWorm. We explored the application of fabric in soft robotics and how textile can be integrated along with other structural elements, such as three-dimensional (3D) printed parts, linear springs, and flexible nylon tubes. The structure of FabricWorm consists of one third the number of rigid pieces as compared to its predecessor Compliant Modular Mesh Worm-Steering (CMMWorm-S), while the structure of MiniFabricWorm consists of no rigid components. This article presents the design of such a mesh and its limitations in terms of structural softness. We experimentally measured the stiffness properties of these robots and compared them directly to its predecessors. FabricWorm and MiniFabricWorm are capable of peristaltic locomotion with a maximum speed of 33 cm/min (0.49 body-lengths/min) and 13.8 cm/min (0.25 body-lengths/min), respectively. Full article

(This article belongs to the Special Issue Selected Papers from Living Machines 2018)

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20 pages, 6068 KiB

Open AccessArticle

A High Coordination of Cross-Links Is Beneficial for the Strength of Cross-Linked Fibers

by Huzaifa Shabbir, Christoph Dellago and Markus A. Hartmann

Biomimetics 2019, 4(1), 12; https://doi.org/10.3390/biomimetics4010012 - 04 Feb 2019

Cited by 13 | Viewed by 4129

Abstract

The influence of the coordination of (reversible) cross-links on the mechanical properties of aligned fiber bundles is investigated. Two polymeric systems containing cross-links of different coordination (two- and three-fold coordination) but having the same binding energy are investigated. In particular, the response to [...] Read more.

The influence of the coordination of (reversible) cross-links on the mechanical properties of aligned fiber bundles is investigated. Two polymeric systems containing cross-links of different coordination (two- and three-fold coordination) but having the same binding energy are investigated. In particular, the response to loading of these systems is compared. Mechanical parameters (strength, stiffness and work-to-fracture) are obtained by computational loading tests. The influence of coordination is studied for simple test systems with pre-defined topologies that maximize strength as well as for more realistic fiber bundles containing nine chains. The results show that a higher coordination of cross-links has a beneficial effect on the strength and the stiffness of the systems, while the work-to-fracture was found larger for the system having a smaller coordination of cross-links. It can be concluded that controlling the coordination of cross-links is a versatile tool to specifically tailor the mechanical properties of polymeric structures. Full article

(This article belongs to the Special Issue Biogenic and Bioinspired Self-Healing Materials)

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10 pages, 2545 KiB

Open AccessArticle

Bioinspired ZnS:Gd Nanoparticles Synthesized from an Endophytic Fungi Aspergillus flavus for Fluorescence-Based Metal Detection

by Priyanka Uddandarao, Raj Mohan Balakrishnan, Apoorva Ashok, Sai Swarup and Priti Sinha

Biomimetics 2019, 4(1), 11; https://doi.org/10.3390/biomimetics4010011 - 01 Feb 2019

Cited by 42 | Viewed by 5343

Abstract

Recently, several nonconventional sources have emerged as strong hotspots for the biosynthesis of chalcogenide quantum dots. However, studies that have ascertained the biomimetic methodologies that initiate biosynthesis are rather limited. The present investigation portrays a few perspectives of rare-earth(Gd)-doped ZnS biosynthesis using the [...] Read more.

Recently, several nonconventional sources have emerged as strong hotspots for the biosynthesis of chalcogenide quantum dots. However, studies that have ascertained the biomimetic methodologies that initiate biosynthesis are rather limited. The present investigation portrays a few perspectives of rare-earth(Gd)-doped ZnS biosynthesis using the endophytic fungi Aspergillus flavus for sensing metals based on their fluorescence. Analysis of ZnS:Gd nanoparticles was performed by elemental analysis, energy-dispersive X-ray spectroscopy (EDS), atomic force microscopy (AFM), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), photoluminescence (PL), and transmission electron microscopy (TEM). The results of TEM demonstrated that the particles were polycrystalline in nature, with a mean size of 10–18 nm. The fluorescence amenability of the biogenic ZnS nanoparticles was further used for the development of a simple and efficient sensing array. The results showed sensitive and detectable quenching/enhancement in the fluorescence of biogenic colloidal ZnS nanoparticles, in the presence of Pb (II), Cd (II), Hg (II), Cu (II) and Ni (II), respectively. The fluorescence intensity of the biogenic ZnS:Gd nanoparticles was found to increase compared to that of the ZnS nanoparticles that capacitate these systems as a reliable fluorescence sensing platform with selective environmental applications. Full article

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6 pages, 194 KiB

Open AccessConference Report

2018 IEEE International Work Conference on Bioinspired Intelligence (IWOBI): Conference Report

by Juan Luis Crespo-Mariño

Biomimetics 2019, 4(1), 9; https://doi.org/10.3390/biomimetics4010009 - 25 Jan 2019

Cited by 1 | Viewed by 2687

Abstract

The International Work Conference on Bioinspired Intelligence (IWOBI) is an annual event that comprises both an international peer-reviewed scientific conference and a set of workshops and other activities in order to foster the research abilities and expertise of young researchers in the field [...] Read more.

The International Work Conference on Bioinspired Intelligence (IWOBI) is an annual event that comprises both an international peer-reviewed scientific conference and a set of workshops and other activities in order to foster the research abilities and expertise of young researchers in the field of bioinspired intelligence. IWOBI 2018 has been characterized by a strong transdisciplinary component. The main conference themes were at the intersection between classical engineering disciplines and computer science, and the life and health sciences. This was motivated by the scientific environment that defines research that is being conducted in Costa Rica. Even though IWOBI is an international event, it was very important for the local organizing committee to focus on knowledge areas that were considered of special interest to Costa Rican researchers and to students looking to start their scientific careers. With such great expectations, IWOBI 2018 has been the first IWOBI conference in history to have parallel tracks. In addition to a regular track, a biocomputation and related techniques track was developed, as well as another one devoted to high-performance computing (HPC) systems applications for life and health sciences applications. Workshops were another important resource developed within IWOBI 2018. They were considered a very important tool in order to foster and train young researchers within the country and they are a very valuable chance to establish direct networking with elite researchers from different countries and research interests. IWOBI 2018 was the first IWOBI conference that implemented real and effective workshops. There were two workshops, one of them devoted to COPASI software and the other one focused on the use of the message passing interface (MPI) parallel programming library. Full article

(This article belongs to the Special Issue Bioinspired Intelligence)

14 pages, 5162 KiB

Open AccessArticle

Analyzing Moment Arm Profiles in a Full-Muscle Rat Hindlimb Model

by Fletcher Young, Christian Rode, Alex Hunt and Roger Quinn

Biomimetics 2019, 4(1), 10; https://doi.org/10.3390/biomimetics4010010 - 25 Jan 2019

Cited by 11 | Viewed by 4896

Abstract

Understanding the kinematics of a hindlimb model is a fundamental aspect of modeling coordinated locomotion. This work describes the development process of a rat hindlimb model that contains a complete muscular system and incorporates physiological walking data to examine realistic muscle movements during [...] Read more.

Understanding the kinematics of a hindlimb model is a fundamental aspect of modeling coordinated locomotion. This work describes the development process of a rat hindlimb model that contains a complete muscular system and incorporates physiological walking data to examine realistic muscle movements during a step cycle. Moment arm profiles for selected muscles are analyzed and presented as the first steps to calculating torque generation at hindlimb joints. A technique for calculating muscle moment arms from muscle attachment points in a three-dimensional (3D) space has been established. This model accounts for the configuration of adjacent joints, a critical aspect of biarticular moment arm analysis that must be considered when calculating joint torque. Moment arm profiles from isolated muscle motions are compared to two existing models. The dependence of biarticular muscle’s moment arms on the configuration of the adjacent joint is a critical aspect of moment arm analysis that must be considered when calculating joint torque. The variability in moment arm profiles suggests changes in muscle function during a step. Full article

(This article belongs to the Special Issue Selected Papers from Living Machines 2018)

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12 pages, 2789 KiB

Open AccessArticle

Real-Time Monitoring of Interactions between Solid-Supported Lipid Vesicle Layers and Short- and Medium-Chain Length Alcohols: Ethanol and 1-Pentanol

by Shova Neupane, George Cordoyiannis, Frank Uwe Renner and Patricia Losada-Pérez

Biomimetics 2019, 4(1), 8; https://doi.org/10.3390/biomimetics4010008 - 22 Jan 2019

Cited by 5 | Viewed by 3379

Abstract

Lipid bilayers represent the interface between the cell and its environment, serving as model systems for the study of various biological processes. For instance, the addition of small molecules such as alcohols is a well-known process that modulates lipid bilayer properties, being considered [...] Read more.

Lipid bilayers represent the interface between the cell and its environment, serving as model systems for the study of various biological processes. For instance, the addition of small molecules such as alcohols is a well-known process that modulates lipid bilayer properties, being considered as a reference for general anesthetic molecules. A plethora of experimental and simulation studies have focused on alcohol’s effect on lipid bilayers. Nevertheless, most studies have focused on lipid membranes formed in the presence of alcohols, while the effect of n-alcohols on preformed lipid membranes has received much less research interest. Here, we monitor the real-time interaction of short-chain alcohols with solid-supported vesicles of dipalmitoylphosphatidylcholine (DPPC) using quartz crystal microbalance with dissipation monitoring (QCM-D) as a label-free method. Results indicate that the addition of ethanol at different concentrations induces changes in the bilayer organization but preserves the stability of the supported vesicle layer. In turn, the addition of 1-pentanol induces not only changes in the bilayer organization, but also promotes vesicle rupture and inhomogeneous lipid layers at very high concentrations. Full article

(This article belongs to the Special Issue Selected Papers from Bioinspired Materials 2018)

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20 pages, 19179 KiB

Open AccessReview

Optimizing Epicardial Restraint and Reinforcement Following Myocardial Infarction: Moving Towards Localized, Biomimetic, and Multitherapeutic Options

by Claudia E. Varela, Yiling Fan and Ellen T. Roche

Biomimetics 2019, 4(1), 7; https://doi.org/10.3390/biomimetics4010007 - 17 Jan 2019

Cited by 10 | Viewed by 5854

Abstract

The mechanical reinforcement of the ventricular wall after a myocardial infarction has been shown to modulate and attenuate negative remodeling that can lead to heart failure. Strategies include wraps, meshes, cardiac patches, or fluid-filled bladders. Here, we review the literature describing these strategies [...] Read more.

The mechanical reinforcement of the ventricular wall after a myocardial infarction has been shown to modulate and attenuate negative remodeling that can lead to heart failure. Strategies include wraps, meshes, cardiac patches, or fluid-filled bladders. Here, we review the literature describing these strategies in the two broad categories of global restraint and local reinforcement. We further subdivide the global restraint category into biventricular and univentricular support. We discuss efforts to optimize devices in each of these categories, particularly in the last five years. These include adding functionality, biomimicry, and adjustability. We also discuss computational models of these strategies, and how they can be used to predict the reduction of stresses in the heart muscle wall. We discuss the range of timing of intervention that has been reported. Finally, we give a perspective on how novel fabrication technologies, imaging techniques, and computational models could potentially enhance these therapeutic strategies. Full article

(This article belongs to the Special Issue Soft Robotics)

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2 pages, 142 KiB

Open AccessEditorial

Acknowledgement to Reviewers of Biomimetics in 2018

by Biomimetics Editorial Office

Biomimetics 2019, 4(1), 6; https://doi.org/10.3390/biomimetics4010006 - 17 Jan 2019

Viewed by 2049

Abstract

Rigorous peer-review is the corner-stone of high-quality academic publishing [...] Full article

11 pages, 1216 KiB

Open AccessArticle

The Effect of Chloride Anions on Charge Transfer in Dye-Sensitized Photoanodes for Water Splitting

by Iwona Grądzka, Mateusz Gierszewski and Marcin Ziółek

Biomimetics 2019, 4(1), 5; https://doi.org/10.3390/biomimetics4010005 - 16 Jan 2019

Cited by 5 | Viewed by 3444

Abstract

The photoelectrochemical behavior of dye-sensitized photoelectrochemical cells based on a TiO₂ layer sensitized with ruthenium components, including an absorber, ruthenium(II)bis(2,2′-bipyridine)([2,2′-bipyridine]-4,4′-diylbis(phosphonic acid)) dibromide (RuP), and a catalyst, ruthenium(II) tris(4-methylpyridine)(4-(4-(2,6-bis((l1-oxidanyl)carbonyl)pyridin-4-yl)phenyl) pyridine-2,6-dicarboxylic acid) (RuOEC), was investigated in the following water-based electrolyte configurations: KCl (pH ≈ [...] Read more.

The photoelectrochemical behavior of dye-sensitized photoelectrochemical cells based on a TiO₂ layer sensitized with ruthenium components, including an absorber, ruthenium(II)bis(2,2′-bipyridine)([2,2′-bipyridine]-4,4′-diylbis(phosphonic acid)) dibromide (RuP), and a catalyst, ruthenium(II) tris(4-methylpyridine)(4-(4-(2,6-bis((l1-oxidanyl)carbonyl)pyridin-4-yl)phenyl) pyridine-2,6-dicarboxylic acid) (RuOEC), was investigated in the following water-based electrolyte configurations: KCl (pH ≈ 5), HCl (pH ≈ 3), ethylphoshonic acid (pH ≈ 3) with a different KCl concentration, and a standard phosphate buffer (pH ≈ 7). The rate of charge transfer on the photoanode’s surface was found to increase in line with the increase in the concentration of chloride anions (Cl⁻) in the low pH electrolyte. This effect is discussed in the context of pH influence, ionic strength, and specific interaction, studied by cyclic voltammetry (CV) in dark conditions and upon illumination of the photoanodes. The correlations between photocurrent decay traces and CV studies were also observed. Full article

(This article belongs to the Special Issue Selected Papers from NanoTech Poland 2018 and 1st Symposium on Polydopamine)

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5 pages, 1036 KiB

Open AccessConference Report

Bioinspired Materials 2018: Conference Report

by Marloes Peeters, Patricia Linton and Araida Hidalgo-Bastida

Biomimetics 2019, 4(1), 4; https://doi.org/10.3390/biomimetics4010004 - 14 Jan 2019

Cited by 2 | Viewed by 3689

Abstract

The Bioinspired Materials conference 2018 was organized for the third time by a team of researchers from Manchester Metropolitan University. This international conference aims to bring together the scientific committee in the fields of biomimetic sensors, bioinspired materials, materials chemistry, three-dimensional (3D) printing, [...] Read more.

The Bioinspired Materials conference 2018 was organized for the third time by a team of researchers from Manchester Metropolitan University. This international conference aims to bring together the scientific committee in the fields of biomimetic sensors, bioinspired materials, materials chemistry, three-dimensional (3D) printing, and tissue engineering. The 2018 edition was held at the John Dalton Building of Manchester Metropolitan University, Manchester, UK, and took place on the 10th of October 2018. There were over 60 national and international attendees, with the international attendees participating in a lab tour through the synthetic facilities and Fuel Cell Innovation Centre on the 9th of October. The three conference sessions encompassed a wide range of topics, varying from biomimetic sensors, hydrogels, and biofabrics and bioengineering. Full article

(This article belongs to the Special Issue Selected Papers from Bioinspired Materials 2018)

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17 pages, 4852 KiB

Open AccessArticle

NDs@PDA@ICG Conjugates for Photothermal Therapy of Glioblastoma Multiforme

by Damian Maziukiewicz, Bartosz F. Grześkowiak, Emerson Coy, Stefan Jurga and Radosław Mrówczyński

Biomimetics 2019, 4(1), 3; https://doi.org/10.3390/biomimetics4010003 - 11 Jan 2019

Cited by 45 | Viewed by 5984

Abstract

The growing incidence of cancer is a problem for modern medicine, since the therapeutic efficacy of applied modalities is still not satisfactory in terms of patients’ survival rates, especially in the case of patients with brain tumors. The destructive influence of chemotherapy and [...] Read more.

The growing incidence of cancer is a problem for modern medicine, since the therapeutic efficacy of applied modalities is still not satisfactory in terms of patients’ survival rates, especially in the case of patients with brain tumors. The destructive influence of chemotherapy and radiotherapy on healthy cells reduces the chances of full recovery. With the development of nanotechnology, new ideas on cancer therapy, including brain tumors, have emerged. Photothermal therapy (PTT) is one of these. It utilizes nanoparticles (NPs) that can convert the light, preferably in the near-infrared (NIR) region, into heat. In this paper, we report the use of nanodiamonds (NDs) conjugated with biomimetic polydopamine (PDA) and indocyanine green (ICG) for glioblastoma cancer PTT therapy. The obtained materials were thoroughly analyzed in terms of their PTT effectiveness, as well as their physicochemical properties. The performed research demonstrated that NDs@PDA@ICG can be successfully applied in the photothermal therapy of glioblastoma for PTT and exhibited high photothermal conversion efficiency η above 40%, which is almost 10 times higher than in case of bare NDs. In regard to our results, our material was found to lead to a better therapeutic outcome and higher eradication of glioblastoma cells, as demonstrated in vitro. Full article

(This article belongs to the Special Issue Selected Papers from NanoTech Poland 2018 and 1st Symposium on Polydopamine)

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13 pages, 4817 KiB

Open AccessArticle

The Friction Properties of Firebrat Scales

by Yuji Hirai, Naoto Okuda, Naoki Saito, Takahiro Ogawa, Ryuichiro Machida, Shûhei Nomura, Masahiro Ôhara, Miki Haseyama and Masatsugu Shimomura

Biomimetics 2019, 4(1), 2; https://doi.org/10.3390/biomimetics4010002 - 04 Jan 2019

Cited by 9 | Viewed by 3863

Abstract

Friction is an important subject for sustainability due to problems that are associated with energy loss. In recent years, micro- and nanostructured surfaces have attracted much attention to reduce friction; however, suitable structures are still under consideration. Many functional surfaces are present in [...] Read more.

Friction is an important subject for sustainability due to problems that are associated with energy loss. In recent years, micro- and nanostructured surfaces have attracted much attention to reduce friction; however, suitable structures are still under consideration. Many functional surfaces are present in nature, such as the friction reduction surfaces of snake skins. In this study, we focused on firebrats, Thermobia domestica, which temporary live in narrow spaces, such as piled papers, so their body surface (integument) is frequently in contact with surrounding substrates. We speculate that, in addition to optical, cleaning effects, protection against desiccation and enemies, their body surface may be also adapted to reduce friction. To investigate the functional effects of the firebrat scales, firebrat surfaces were observed using a field-emission scanning electron microscope (FE-SEM) and a colloidal probe atomic force microscope (AFM). Results of surface observations by FE-SEM revealed that adult firebrats are entirely covered with scales, whose surfaces have microgroove structures. Scale groove wavelengths around the firebrat’s head are almost uniform within a scale but they vary between scales. At the level of single scales, AFM friction force measurements revealed that the firebrat scale reduces friction by decreasing the contact area between scales and a colloidal probe. The heterogeneity of the scales’ groove wavelengths suggests that it is difficult to fix the whole body on critical rough surfaces and may result in a “fail-safe” mechanism. Full article

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14 pages, 2328 KiB

Open AccessArticle

Mechanical Modeling of Healthy and Diseased Calcaneal Fat Pad Surrogates

by Arnab Chanda and Stephen McClain

Biomimetics 2019, 4(1), 1; https://doi.org/10.3390/biomimetics4010001 - 03 Jan 2019

Cited by 12 | Viewed by 5671

Abstract

The calcaneal fat pad is a major load bearing component of the human foot due to daily gait activities such as standing, walking, and running. Heel and arch pain pathologies such as plantar fasciitis, which over one third of the world population suffers [...] Read more.

The calcaneal fat pad is a major load bearing component of the human foot due to daily gait activities such as standing, walking, and running. Heel and arch pain pathologies such as plantar fasciitis, which over one third of the world population suffers from, is a consequent effect of calcaneal fat pad damage. Also, fat pad stiffening and ulceration has been observed due to diabetes mellitus. To date, the biomechanics of fat pad damage is poorly understood due to the unavailability of live human models (because of ethical and biosafety issues) or biofidelic surrogates for testing. This also precludes the study of the effectiveness of preventive custom orthotics for foot pain pathologies caused due to fat pad damage. The current work addresses this key gap in the literature with the development of novel biofidelic surrogates， which simulate the in vivo and in vitro compressive mechanical properties of a healthy calcaneal fat pad. Also, surrogates were developed to simulate the in vivo mechanical behavior of the fat pad due to plantar fasciitis and diabetes. A four-part elastomeric material system was used to fabricate the surrogates, and their mechanical properties were characterized using dynamic and cyclic load testing. Different strain (or displacement) rates were tested to understand surrogate behavior due to high impact loads. These surrogates can be integrated with a prosthetic foot model and mechanically tested to characterize the shock absorption in different simulated gait activities, and due to varying fat pad material property in foot pain pathologies (i.e., plantar fasciitis, diabetes, and injury). Additionally, such a foot surrogate model, fitted with a custom orthotic and footwear, can be used for the experimental testing of shock absorption characteristics of preventive orthoses. Full article

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Biomimetics, Volume 4, Issue 1 (March 2019) – 28 articles

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