In the last 30 days

• Open/close Distributed mechanical feedback in arthropods and robots simplifies control of rapid running on challenging terrain

  J C Spagna et al  2007 Bioinspir. Biomim. 2 9 Tag this article

  Article References Full text PDF (1.68 MB)

  Terrestrial arthropods negotiate demanding terrain more effectively than any search-and-rescue robot. Slow, precise stepping using distributed neural feedback is one strategy for dealing with challenging terrain. Alternatively, arthropods could simplify control on demanding surfaces by rapid running that uses kinetic energy to bridge gaps between footholds. We demonstrate that this is achieved using distributed mechanical feedback, resulting from passive contacts along legs positioned by pre-programmed trajectories favorable to their attachment mechanisms. We used wire-mesh experimental surfaces to determine how a decrease in foothold probability affects speed and stability. Spiders and insects attained high running speeds on simulated terrain with 90% of the surface contact area removed. Cockroaches maintained high speeds even with their tarsi ablated, by generating horizontally oriented leg trajectories. Spiders with more vertically directed leg placement used leg spines, which resulted in more effective distributed contact by interlocking with asperities during leg extension, but collapsing during flexion, preventing entanglement. Ghost crabs, which naturally lack leg spines, showed increased mobility on wire mesh after the addition of artificial, collapsible spines. A bioinspired robot, RHex, was redesigned to maximize effective distributed leg contact, by changing leg orientation and adding directional spines. These changes improved RHex's agility on challenging surfaces without adding sensors or changing the control system.

• Open/close Software techniques for two- and three-dimensional kinematic measurements of biological and biomimetic systems

  Tyson L Hedrick  2008 Bioinspir. Biomim. 3 034001 Tag this article

  Article References Full text PDF (217 KB)

  Researchers studying aspects of locomotion or movement in biological and biomimetic systems commonly use video or stereo video recordings to quantify the behaviour of the system in question, often with an emphasis on measures of position, velocity and acceleration. However, despite the apparent simplicity of video analysis, it can require substantial investment of time and effort, even when performed with adequate software tools. This paper reviews the underlying principles of video and stereo video analysis as well as its automation and is accompanied by fully functional and freely available software implementation.

• Open/close Artificial lateral line with biomimetic neuromasts to emulate fish sensing

  Yingchen Yang et al  2010 Bioinspir. Biomim. 5 016001 Tag this article

  Article References Full text PDF (1.35 MB)

  Hydrodynamic imaging using the lateral line plays a critical role in fish behavior. To engineer such a biologically inspired sensing system, we developed an artificial lateral line using MEMS (microelectromechanical system) technology and explored its localization capability. Arrays of biomimetic neuromasts constituted an artificial lateral line wrapped around a cylinder. A beamforming algorithm further enabled the artificial lateral line to image real-world hydrodynamic events in a 3D domain. We demonstrate that the artificial lateral line system can accurately localize an artificial dipole source and a natural tail-flicking crayfish under various conditions. The artificial lateral line provides a new sense to man-made underwater vehicles and marine robots so that they can sense like fish.

• Open/close The role of intrinsic muscle properties for stable hopping—stability is achieved by the force–velocity relation

  D F B Haeufle et al  2010 Bioinspir. Biomim. 5 016004 Tag this article

  Article References Full text PDF (666 KB)

  A reductionist approach was presented to investigate which level of detail of the physiological muscle is required for stable locomotion. Periodic movements of a simplified one-dimensional hopping model with a Hill-type muscle (one contractile element, neither serial nor parallel elastic elements) were analyzed. Force–length and force–velocity relations of the muscle were varied in three levels of approximation (constant, linear and Hill-shaped nonlinear) resulting in nine different hopping models of different complexity. Stability of these models was evaluated by return map analysis and the performance by the maximum hopping height. The simplest model (constant force–length and constant force–velocity relations) outperformed all others in the maximum hopping height but was unstable. Stable hopping was achieved with linear and Hill-shaped nonlinear characteristic of the force–velocity relation. The characteristics of the force–length relation marginally influenced hopping stability. The results of this approach indicate that the intrinsic properties of the contractile element are responsible for stabilization of periodic movements. This connotes that (a) complex movements like legged locomotion could benefit from stabilizing effects of muscle properties, and (b) technical systems could benefit from the emerging stability when implementing biological characteristics into artificial muscles.

• Open/close Micromachined biomimetic artificial haircell sensors

  Chang Liu  2007 Bioinspir. Biomim. 2 S162 Tag this article

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  The biological haircell is a modular building block of a rich variety of biological sensors. Using micro- and nanofabrication technology, an engineering equivalent artificial haircell sensor can be developed, imitating the structure and transfer function of the biological haircell. The artificial haircells can be made of hybrid semiconductor, metal and polymers. This paper discusses a number of strategies, using representative material systems, for building artificial haircell sensors and briefly outlines their fabrication method and performance. The motivation for imitating the biological haircell is also discussed to provide a background for this work.

• Open/close Coaxially electrospun micro/nanofibrous poly(ε-caprolactone)/eggshell-protein scaffold

  Geun Hyung Kim et al  2008 Bioinspir. Biomim. 3 016006 Tag this article

  Article References Full text PDF (1.64 MB)

  Eggshell membrane (ESM) has potential as a natural scaffold because of its highly porous structure and good biocompatibility. To mimic its structure and surface properties, soluble eggshell membrane protein (SEP) was extracted from ESM and electrospun with a biodegradable polymer, poly(ε-caprolactone) (PCL). SEP/PCL micro/nanofibers were fabricated using a coaxial electrospinning process with a dual nozzle and an auxiliary cylindrical electrode. The fiber web was characterized using the water contact angle, pore-size distribution, mechanical properties and cellular behavior. The SEP/PCL web, which demonstrated the feasibility of producing a scaffold with adequate hydrophilicity, suitable pore size and good mechanical properties compared to a pure PCL micro/nanofiber web, exhibits the ability to mimic a natural biomaterial.

• Open/close Direct measurements of the kinematics and dynamics of bat flight

  Xiaodong Tian et al  2006 Bioinspir. Biomim. 1 S10 Tag this article

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  Experimental measurements and analysis of the flight of bats are presented, including kinematic analysis of high-speed stereo videography of straight and turning flight, and measurements of the wake velocity field behind the bat. The kinematic data reveal that, at relatively slow flight speeds, wing motion is quite complex, including a sharp retraction of the wing during the upstroke and a broad sweep of the partially extended wing during the downstroke. The data also indicate that the flight speed and elevation are not constant, but oscillate in synchrony with both the horizontal and vertical movements of the wing. PIV measurements in the transverse ( Trefftz) plane of the wake indicate a complex 'wake vortex' structure dominated by a strong wing tip vortex shed from the wing tip during the downstroke and either the wing tip or a more proximal joint during the upstroke. Data synthesis of several discrete realizations suggests a 'cartoon' of the wake structure during the entire wing beat cycle. Considerable work remains to be done to confirm and amplify these results.

• Open/close Mechanics of a mosquito bite with applications to microneedle design

  M K Ramasubramanian et al  2008 Bioinspir. Biomim. 3 046001 Tag this article

  Article References Full text PDF (830 KB)

  The mechanics of a fascicle insertion into the skin by a mosquito of the type aedes aegypti has been studied experimentally using high-speed video (HSV) imaging, and analytically using a mathematical model. The fascicle is a polymeric microneedle composed of a ductile material, chitin. It has been proposed that the mosquito applies a non-conservative follower force component in addition to the Euler compressive load in order to prevent buckling and penetrate the skin. In addition, the protective sheath surrounding the fascicle (labium) provides lateral support during insertion. The mechanics model presented approximates the fascicle as a slender column supported on an elastic foundation (labium) subjected to non-conservative (Beck) and conservative Euler loads simultaneously at the end. Results show that the lateral support of the fascicle provided by the labium is essential for successful penetration by increasing the critical buckling load by a factor of 5. The non-conservative follower force application increases the buckling load by an additional 20% and may or may not be necessary for successful penetration. Experimental results showing the importance of the labium have been cited to validate the model predictions, in addition to the video observations presented in this work. This understanding may be useful in designing painless needle insertion systems as opposed to miniaturized hypodermic needles.

• Open/close Biomimetics—using nature to inspire human innovation

  Yoseph Bar-Cohen  2006 Bioinspir. Biomim. 1 P1 Tag this article

  Article References Full text PDF (851 KB)

  Evolution has resolved many of nature's challenges leading to lasting solutions. Nature has always inspired human achievements and has led to effective materials, structures, tools, mechanisms, processes, algorithms, methods, systems, and many other benefits (Bar-Cohen Y (ed) 2005 Biomimetics—Biologically Inspired Technologies (Boca Raton, FL: CRC Press) pp 1–552). This field, which is known as biomimetics, offers enormous potential for inspiring new capabilities for exciting future technologies. There are numerous examples of biomimetic successes that involve making simple copies, such as the use of fins for swimming. Others examples involved greater mimicking complexity including the mastery of flying that became possible only after the principles of aerodynamics were better understood. Some commercial implementations of biomimetics, including robotic toys and movie subjects, are increasingly appearing and behaving like living creatures. More substantial benefits of biomimetics include the development of prosthetics that closely mimic real limbs and sensory-enhancing microchips that are interfaced with the brain to assist in hearing, seeing and controlling instruments. A review is given of selected areas that were inspired by nature, and an outlook for potential development in biomimetics is presented.

• Open/close A mechanical model of biomimetic adhesive pads with tilted and hierarchical structures

  M Schargott  2009 Bioinspir. Biomim. 4 026002 Tag this article

  Article References Full text PDF (1.29 MB)

  A 3D model for hierarchical biomimetic adhesive pads is constructed. It is based on the main principles of the adhesive pads of the Tokay gecko and consists of hierarchical layers of vertical or tilted beams, where each layer is constructed in such a way that no cohesion between adjacent beams can occur. The elastic and adhesive properties are calculated analytically and numerically. For the adhesive contact on stochastically rough surfaces, the maximum adhesion force increases with increasing number of hierarchical layers. Additional calculations show that the adhesion force also depends on the height spectrum of the rough surface.