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Bioinspiration & Biomimetics

Manfred Hartbauer
Modern cars are equipped with both active and passive sensor systems that can detect potential collisions. In contrast, locusts avoid collisions solely by responding to certain visual cues that are associated with object looming. In neurophysiological experiments, I investigated the possibility that "collision-detector neurons��� of locusts respond to impending collisions in films recorded with dashboard cameras of fast driving cars. In a complementary modelling approach, I developed a simple algorithm to reproduce the neuronal response that was recorded during object approach...
January 16, 2017: Bioinspiration & Biomimetics
Jaime Gustav Wong, Benen laBastide, David Rival
The growth of leading-edge vortices (LEV) on analogous flapping and rotating profiles has been investigated experimentally. Three time-varying cases were considered: a two-dimensional reference case with a spanwise-uniform angle-of-attack variation $\alpha$; a case with increasing �� towards the profile tip (similar to flapping flyers); and a case with increasing �� towards the profile root (similar to rotor blades experiencing an axial gust). It has been shown that the time-varying spanwise angle-of-attack gradient produces a vorticity gradient, which, in combination with spanwise flow, results in a redistribution of circulation along the profile...
January 13, 2017: Bioinspiration & Biomimetics
Chao Zhang, Claudio Rossi
Flapping-wing micro air vehicles (FWMAVs) are a class of unmanned aircraft that imitate flight characteristics of natural organisms such as birds, bats, and insects, in order to achieve maximum flight efficiency and manoeuvrability. Designing proper mechanisms for flapping transmission is an extremely important aspect for FWMAVs. Compliant transmission mechanisms have been considered as an alternative to rigid transmission systems due to their lower the number of parts, thereby reducing the total weight, lower energy loss thanks to little or practically no friction among parts, and at the same time, being able to store and release mechanical power during the flapping cycle...
January 11, 2017: Bioinspiration & Biomimetics
Chengyu Li, Haibo Dong
This study integrates high-speed photogrammetry, three-dimensional surface reconstruction, and computational fluid dynamics to explore a dragonfly (Erythemis Simplicicollis) in free flight. Asymmetric wing kinematics and the associated aerodynamic characteristics of a turning dragonfly are analyzed in detail. Quantitative measurements of wing kinematics show that compared to the outer wings, the inner wings sweep more slowly with a higher angle of attack during the downstroke, whereas they flap faster with a lower angle of attack during the upstroke...
January 6, 2017: Bioinspiration & Biomimetics
Amy Lang, Emily Jones, Farhana Afroz
Over many decades the biological surfaces of aquatic swimmers have been studied for their potential as drag reducing surfaces. The hydrodynamic benefit of riblets, or grooves embedded parallel to the flow which appear on surfaces such as shark skin, have been well documented. However the skin of dolphins is embedded with sinusoidal grooves that run perpendicular or transverse to the flow over their bodies. It is theorized that the transverse grooves present on dolphin skin trap vortices between them, creating a partial slip condition over the surface and inducing turbulence augmentation in the boundary layer, thus acting as a potential mechanism to reduce flow separation and thus pressure drag...
January 6, 2017: Bioinspiration & Biomimetics
Gwang-Pil Jung, Hong-Cheol Choi, Kyu-Jin Cho
Inspired by the relationship between leg compliance and jumping performance in the false stick insect, this paper describes how variations in leg compliance and jumping direction affect the performance of a flea-inspired jumping mechanism. The amount of energy lost during jumping was determined by examining the ratio of kinetic energy to input energy (also called conversion efficiency). Leg compliance is modeled based on the compliant mechanics to determine energy transfer during jumping and determined the optimum degree of leg compliance for maximizing performance...
January 6, 2017: Bioinspiration & Biomimetics
Joost Geeroms, Louis Flynn, Rene Enrique Jimenez Fabian, Bram Vanderborght, Dirk Lefeber
There are disadvantages to existing damping knee prostheses which cause an asymmetric gait and higher metabolic cost during level walking compared to non-amputees. Most existing active knee prostheses which could benefit the amputees use a significant amount of energy and require a considerable motor. In this work, a novel semi-active actuator with a lockable parallel spring for a prosthetic knee joint has been developed and tested. This actuator is able to provide an approximation of the behavior of a healthy knee during most of the gait cycle of level walking...
January 6, 2017: Bioinspiration & Biomimetics
Paolo Tommasino, Domenico Campolo
In this work, we address human-like motor planning in redundant manipulators. Specifically, we want to capture postural synergies such as Donders' law, experimentally observed in humans during kinematically redundant tasks, and infer a minimal set of parameters to implement similar postural synergies in a kinematic model. For the model itself, although the focus of this paper is to solve redundancy by implementing postural strategies derived from experimental data, we also want to ensure that such postural control strategies do not interfere with other possible forms of motion control (in the task space), i...
December 22, 2016: Bioinspiration & Biomimetics
Nathan Slegers, Michael Heilman, Jacob Cranford, Amy Lang, John Yoder, Maria Habegger
It is hypothesized that butterfly wing scale geometry and surface patterning may function to improve aerodynamic efficiency. In order to investigate this hypothesis, a method to measure butterfly flapping kinematics optically over long uninhibited flapping sequences was developed. Statistical results for the climbing flight flapping kinematics of 11 butterflies, based on a total of 236 individual flights, both with and without their wing scales, are presented. Results show, that for each of the 11 butterflies, the mean climbing efficiency decreased after scales were removed...
December 21, 2016: Bioinspiration & Biomimetics
Duo-Neng Liu, Zhong-Xi Hou, Zheng Guo, Xi-Xiang Yang, Xian-Zhong Gao
Albatrosses can make use of the dynamic soaring technique extracting energy from the wind field to achieve large-scale movement without a flap, which stimulates interests in effortless flight with small unmanned aerial vehicles (UAVs). However, mechanisms of energy harvesting in terms of the energy transfer from the wind to the flyer (albatross or UAV) are still indeterminate and controversial when using different reference frames in previous studies. In this paper, the classical four-phase Rayleigh cycle, includes sequentially upwind climb, downwind turn, downwind dive and upwind turn, is introduced in analyses of energy gain with the albatross's equation of motions and the simulated trajectory in dynamic soaring...
December 19, 2016: Bioinspiration & Biomimetics
Haijie Zhang, Jianguo Zhao
Marvelous vision based dynamic behaviors of insects and birds such as perching, landing, and obstacle avoidance have inspired scientists to propose the idea of time-to-contact, which is defined as the time for a moving observer to contact an object or surface if the current velocity is maintained. Since with only a vision sensor, time-to-contact can be directly estimated from consecutive images, it is widely used for a variety of robots to fulfill various tasks such as obstacle avoidance, docking, chasing, perching and landing...
December 14, 2016: Bioinspiration & Biomimetics
L Zheng, M Behrooz, F Gordaninejad
This work presents an adaptive structure inspired by spider webs' behavior. To investigate the dynamic properties and performance of this system, numerical models are developed to examine the effects of pretension in radial strings, and Young's modulus, and damping ratio on the natural frequency and total energy of the system. An experimental study was conducted to validate theoretical results. Stepper motors controlled by a microcontroller are utilized to increase the pretension in the radial strings of the web in order to tune the web's energy absorption ability...
January 17, 2017: Bioinspiration & Biomimetics
Mariel-Luisa N Rosic, Patrick J M Thornycroft, Kara L Feilich, Kelsey N Lucas, George V Lauder
Tuna are fast, economical swimmers in part due to their stiff, high aspect ratio caudal fins and streamlined bodies. Previous studies using passive caudal fin models have suggested that while high aspect ratio tail shapes such as a tuna's generally perform well, tail performance cannot be determined from shape alone. In this study, we analyzed the swimming performance of tuna-tail-shaped hydrofoils of a wide range of stiffnesses, heave amplitudes, and frequencies to determine how stiffness and kinematics affect multiple swimming performance parameters for a single foil shape...
January 17, 2017: Bioinspiration & Biomimetics
Vipul Sharma, Suneel Kumar, Ashish Bahuguna, Diksha Gambhir, Prateep Singh Sagara, Venkata Krishnan
This work presents a novel approach of using natural plant leaf surfaces having intricate hierarchical structures as scaffolds for Pd nanoparticles and demonstrated it as a Green dip catalyst for Suzuki-Miyaura coupling reactions in water. The influence of the topographical texture of the plant leaves on the deposition and catalytic properties of Pd nanoparticles are presented and discussed. The catalytic activity can be correlated to the surface texture of the leaves, wherein it has been found that the micro/nanostructures present on the surface strongly influence the assembly and entrapment of the nanoparticles, and thereby control aggregation and leaching of the catalysts...
December 21, 2016: Bioinspiration & Biomimetics
A Sadeghi, A Mondini, E Del Dottore, V Mattoli, L Beccai, S Taccola, C Lucarotti, M Totaro, B Mazzolai
We present the design and development of a plant-inspired robot, named Plantoid, with sensorized robotic roots. Natural roots have a multi-sensing capability and show a soft bending behaviour to follow or escape from various environmental parameters (i.e., tropisms). Analogously, we implement soft bending capabilities in our robotic roots by designing and integrating soft spring-based actuation (SSBA) systems using helical springs to transmit the motor power in a compliant manner. Each robotic tip integrates four different sensors, including customised flexible touch and innovative humidity sensors together with commercial gravity and temperature sensors...
December 20, 2016: Bioinspiration & Biomimetics
Farhana Afroz, Amy Lang, Maria Laura Habegger, Philip Motta, Robert Hueter
The Shortfin Mako shark (Isurus oxyrinchus) is a fast swimmer and has incredible turning agility, and has flexible scales known to bristle up to 50° in the flank regions. It is purported that this bristling capability of the scales may result in a unique pass flow control method to control flow separation and reduce drag. It appears that the scales have evolved to be only actuated when the flow over the body is reversed; thereby inducing a method of inhibiting flow reversal close to the surface. In addition, bristled scales form cavities which could induce boundary layer mixing and further assist in delaying flow separation...
December 20, 2016: Bioinspiration & Biomimetics
Suyi Li, K W Wang
Plants exhibit a variety of reversible motions, from the slow opening of pine cones to the impulsive closing of Venus flytrap leaves. These motions are achieved without muscles and they have inspired a wide spectrum of engineered materials and structures. This review summarizes the recent developments of plant-inspired adaptive structures and materials for morphing and actuation. We begin with a brief overview of the actuation strategies and physiological features associated to these plant movements, showing that different combinations of these strategies and features can lead to motions with different deformation characteristics and response speeds...
December 20, 2016: Bioinspiration & Biomimetics
Sandra Fang, Michael Peshkin, Malcolm A MacIver
Active electrosense is a non-visual, short range sensing system used by weakly electric fish, enabling such fish to locate and identify objects in total darkness. Here we report initial findings from the use of active electrosense for object localization during underwater teleoperation with a virtual reality (VR) head-mounted display (HMD). The advantage of electrolocating with a VR system is that it naturally allows for aspects of the task that are difficult for a person to perform to be allocated to the computer...
December 20, 2016: Bioinspiration & Biomimetics
D Ishihara, T Horie
The high torsional flexibility of insect wings allows for elastic recoil after the rotation of the wing during stroke reversal. However, the underlying mechanism of this recoil remains unclear because of the dynamic process of transitioning from the wing rotation during stroke reversal to the maintenance of a high angle of attack during the middle of each half-stroke, when the inertial, elastic, and aerodynamic effects all have a significant impact. Therefore, the interaction between the flapping wing and the surrounding air was directly simulated by simultaneously solving the incompressible Navier-Stokes equations, the equation of motion for an elastic body, and the fluid-structure interface conditions using the three-dimensional finite element method...
December 20, 2016: Bioinspiration & Biomimetics
Anh Tuan Nguyen, Jong-Seob Han, Jae-Hung Han
This study explores the effects of the body aerodynamics on the dynamic flight stability of an insect at various different forward flight speeds. The insect model, whose morphological parameters are based on measurement data from the hawkmoth Manduca sexta, is treated as an open-loop six-degree-of-freedom dynamic system. The aerodynamic forces and moments acting on the insect are computed by an aerodynamic model that combines the unsteady panel method and the extended unsteady vortex-lattice method. The aerodynamic model is then coupled to a multi-body dynamic code to solve the system of motion equations...
December 14, 2016: Bioinspiration & Biomimetics
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