Bioinspiration & Biomimetics

The human toe, characterized by its rigid-flexible structure comprising hard bones and flexible joints, facilitates adaptive and stable movement across varied terrains. In this paper, we utilized a motion capture system to study the adaptive adjustments of toe joints when encountering obstacles. Inspired by the mechanics of toe joints, we proposed a novel design method for a rigid-flexible coupled wheel. The wheel comprises multiple elements: a rigid skeleton, supporting toes, connecting shafts, torsion springs, soft tendons, and damping pads...

This paper presents a bibliometrics analysis aimed at discerning global trends in research on "biomimetics", "biomimicry", "bionics", and "bio-inspired" concepts within civil engineering, using the Scopus database. This database facilitates the assessment of interrelationships and impacts of these concepts within the civil engineering domain. The findings demonstrate a consistent growth in publications related to these areas, indicative of increasing interest and impact within the civil engineering community...

Soft-bodied animals, such as worms and snakes, use many muscles in different ways to traverse unstructured environments and inspire tools for accessing confined spaces. They demonstrate versatility of locomotion which is essential for adaptation to changing terrain conditions. However, replicating such versatility in untethered soft-bodied robots with multimodal locomotion capabilities have been challenging due to complex fabrication processes and limitations of soft body structures to accommodate hardware such as actuators, batteries and circuit boards...

This paper presents a novel approach for designing a fail-safe bending-resistant structure from the combination of explicit discrete component-based topology optimization and the porcupine quill-inspired features. To achieve fail-safe functionalities under classical topology optimization formulations, the method involves constructing discrete components at various scales to imitate the quill's foam-like characteristics. The components are iteratively updated, and the optimization process allows for the grading of quill-inspired features while achieving optimal structural compliance under bending loads...

To improve the adaptability of soft robots to the environment and achieve reliable attachment on various surfaces such as smooth and rough, this study draws inspiration from the collaborative attachment strategy of insects, cats, and other biological claw hooks and foot pads, and designs an actuator with a bionic claw hook-suction cup hybrid structure. The rigid biomimetic pop-up claw hook linkage mechanism is combined with a flexible suction cup of a "foot pad" to achieve a synergistic adhesion effect between claw hook locking and suction cup adhesion through the deformation control of a soft pneumatic actuator...

Animals have evolved highly effective locomotion capabilities in terrestrial, aerial, and aquatic
environments. Over life's history, mass extinctions have wiped out unique animal species with specialized
adaptations, leaving paleontologists to reconstruct their locomotion through fossil analysis. Despite
advancements, little is known about how extinct megafauna, such as the Ichthyosauria one of the most
successful lineages of marine reptiles, utilized their varied morphologies for swimming...

In nature, leaves and their laminae vary in shape, appearance and unfolding behaviour. We investigated peltate leaves of two model species with peltate leaves and highly different morphology (Syngonium podophyllum and Pilea peperomioides) and two distinct unfolding patterns via time-lapse recordings: we observed successive unfolding of leaf halves in S. podophyllum and simultaneous unfolding in P. peperomioides. Furthermore, we gathered relevant morphological and biomechanical data in juvenile (unfolding) and adult (fully unfolded) plants of both species by measuring the thickness and the tensile modulus of both lamina and veins as a measure of their stiffness...

Combining different biological features exhibiting different functions is necessary to generate uncommon and unique multifunctional bio-inspired conceptual designs. Different biological features independently evolve characteristics to solve the same need/necessity. This phenomenon is called convergent evolution. Without parameters, selecting a suitable feature from those that exhibit the same function and have the same geometric relevance becomes quite difficult. This research investigates and identifies the parameters that have the potential to support choosing the suitable biological feature and to support the multifunctional design concept generation...

Biological materials such as bone, nacre, antler, and teeth are gifted with excellent mechanical properties that have inspired synthetic composites' development. These superior properties are attributed to the geometrical as well as the material properties of the constituents at a small scale. This paper is focused on the influence of failure modes over the mechanical properties including stiffness, strength, and toughness, after the failure of different interfaces in staggered bio-inspired structures such as regular and stairwise staggered arrangements where stiff platelets are embedded in a pliant matrix...

Nature is filled with materials that are both strong and light, such as bones, teeth, bamboo, seashells, arthropod exoskeletons, and nut shells. The insights gained from analyzing the changing chemical compositions and structural characteristics, as well as the mechanical properties of these materials, have been applied in developing innovative, durable, and lightweight materials like those used for impact absorption. This research concentrates on the involucres of Job's tears (Coix lacryma-jobi var. lacryma-jobi), which are rich in silica, hard, and serve to encase the seeds...

African shrimp (Atya gabonensis) inhabit clear freshwaters, where the notably low concentration of food may pose a challenge to the efficacy of filter fibers on the chela for filter-feeding. Here, we investigate how the distinctive cross-sectional characteristics and spatial arrangement of the African shrimp's non-circular fibers contribute to the enhanced filtration performance of these specialized fibers. The unilateral thickening of the wall along the long axis of the elliptical cross-section of African shrimp fibers markedly enhances the filtration performance...

In the field of robotic hands, finger force coordination is usually achieved by complex mechanical structures and control systems. This study presents the design of a novel transmission system inspired from the physiological concept of force synergies, aiming to simplify the control of multifingered robotic hands. To this end, we collected human finger force data during six isometric grasping tasks, and force synergies (i.e., the synergy weightings and the corresponding activation coefficients) were extracted from the concatenated force data to explore their potential for force modulation...

Computational models are used to examine the effect of schooling on flow generated noise of fish swimming using their caudal fins. We simulate the flow as well as the far-field hydrodynamic sound generated by the time-varying pressure loading on these carangiform swimmers. The effect of the number of swimmers in the school, the relative phase of fin flapping of the swimmers, and their spatial arrangement is examined. The simulations indicate that the phase of the fin flapping is a dominant factor in the total sound radiated into the far-field by a group of swimmers...

The silent flight of barn owls is associated with wing and feather specialisations. Three special
features are known: a serrated leading edge that is formed by free-standing barb tips which
appears as a comb-like structure, a soft dorsal surface, and a fringed trailing edge. We used
a model of the leading edge comb with 3D-curved serrations that was designed based on 3D
micro-scans of rows of barbs from selected barn-owl feathers. The interaction of the flow with
the serrations was measured with Particle-Image-Velocimetry in a flow channel at uniform steady
inflow and was compared to the situation of inflow with freestream turbulence, generated from
the turbulent wake of a cylinder placed upstream...

The urgency for energy efficient, responsive architectures has propelled smart material development to the forefront of scientific and architectural research. This paper explores biological, physical, and morphological factors influencing the programming of a novel microbial-based smart hybrid material which is responsive to changes in environmental humidity. Hygromorphs respond passively, without energy input, by expanding in high humidity and contracting in low humidity. Bacillus subtilis develops environmentally robust, hygromorphic spores which may be harnessed within a bilayer to generate a deflection response with potential for programmability...

In this work, we focus on overcoming the challenge of a snake robot climbing on the outside of a bifurcated pipe. Inspired by the climbing postures of biological snakes, we propose an S-shaped rolling gait designed using curve transformations. For this gait, the snake robot's body presenting an S-shaped curve is wrapped mainly around one side of the pipe, which leaves space for the fork of the pipe. To overcome the difficulty in constructing and clarifying the S-shaped curve, we present a method for establishing the transformation between a plane curve and a 3D curve on a cylindrical surface...

Recognizing humans' unmatched robustness, adaptability, and learning abilities across anthropomorphic movements compared to robots, we find inspiration in the simultaneous development of both morphology and cognition observed in humans. We utilize optimal control principles to train a muscle-actuated human model for both balance and squat jump tasks in simulation. Morphological development is introduced through abrupt transitions from a 4-year-old to a 12-year-old morphology, ultimately shifting to an adult morphology...

A limiting factor in the design of smaller size uncrewed aerial vehicles is their inability to navigate through gust-laden environments. As a result, engineers have turned towards bio-inspired engineering approaches for gust mitigation techniques. In this study, the aerodynamics of a red-tailed hawk's response to variable-magnitude discrete transverse gusts was investigated. The hawk was flown in an indoor flight arena instrumented by multiple high-speed cameras to quantify the 3D motion of the bird as it navigated through the gust...

Over the past few years, the research community has witnessed a burgeoning interest in biomimetics, particularly within the marine sector. The study of biomimicry as a revolutionary remedy for numerous commercial and research-based marine businesses has been spurred by the difficulties presented by the harsh maritime environment. Biomimetic marine robots are at the forefront of this innovation by imitating various structures and behaviours of marine life and utilizing the evolutionary advantages and adaptations these marine organisms have developed over millennia to thrive in harsh conditions...

Bioinspired Flapping-Wing Micro Aerial Vehicles (FWMAVs) have
emerged over the last two decades as a promising new type of robot. Their high thrustto-
weight ratio, versatility, safety, and maneuverability, especially at small scales,
could make them more suitable than fixed-wing and multi-rotor vehicles for various
applications, especially in cluttered, confined environments and in close proximity to
humans, flora, and fauna. Unlike natural flyers, however, most FWMAVs currently
have limited take-off and landing capabilities...