Towards understanding of climbing, tip-over prevention and self-righting behaviors in Hexapoda

Die vorliegende Dissertation mit dem Titel “Towards understanding of climbing, tip-over prevention and self-righting behaviors in Hexapoda” untersucht in drei Studien exemplarisch, wie (i) Wüstenameisen ihre Beine einsetzen um An- und Abstiege zu überwinden, wie (ii) Wüsten- und Waldameisen ein Umkippen an steilen Anstiegen vermeiden, und wie sich (iii) Madagaskar-Fauchschaben, Amerikanische Großschaben und Blaberus discoidalis Audinet-Servill, 1839 aus Rückenlagen drehen und aufrichten. Neuartige biomechanischen Beschreibungen umfassen unter anderem: Impuls- und Kraftwirkungen einzelner Ameisenbeine auf den Untergrund beim Bergauf- und Bergabklettern, Kippmomente bei kletternden Ameisen, Energiegebirge-Modelle (energy landscapes) zur Quantifizierung der Körperform für die funktionelle Beschreibung des Umdrehens aus der Rückenlage

On Plume Dispersion after Line Source in Crossflows over Rough Surfaces

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Injury and Skeletal Biomechanics

This book covers many aspects of Injury and Skeletal Biomechanics. As the title represents, the aspects of force, motion, kinetics, kinematics, deformation, stress and strain are examined in a range of topics such as human muscles and skeleton, gait, injury and risk assessment under given situations. Topics range from image processing to articular cartilage biomechanical behavior, gait behavior under different scenarios, and training, to musculoskeletal and injury biomechanics modeling and risk assessment to motion preservation. This book, together with "Human Musculoskeletal Biomechanics", is available for free download to students and instructors who may find it suitable to develop new graduate level courses and undergraduate teaching in biomechanics

Data-Driven Methods for Geometric Systems

The tools of geometric mechanics provide a compact representation of locomotion dynamics as ``the reconstruction equation''. We have found this equation yields a convenient form for estimating models directly from observation data. This convenience draws from the method's relatively rare feature of providing high accuracy models with little effort. By little effort, we point to the modeling process's low data requirements and the property that nothing about the implementation changes when substituting robot kinematics, material properties, or environmental conditions, as long as some intuitive baseline features of the dynamics are shared. We have applied data-driven geometric mechanics models toward optimizing robot behaviors both physical and simulated, exploring robots' ability to recover from injury, and efficiently creating libraries of maneuvers to be used as building blocks for higher-level robot tasks. Our methods employed the tools of data-driven Floquet analysis, providing a phase that we used as a means of grouping related measurements, allowing us to estimate a reconstruction equation model as a function of phase in the neighborhood of an observed behavior. This tool allowed us to build models at unanticipated scales of complexity and speed. Our use of a perturbation expansion for the geometric terms led to an improved estimation procedure for highly damped systems containing nontrivial but non-dominating amounts of momentum. Analysis of the role of passivity in dissipative systems led to another extension of the estimation procedure to robots with high degrees of underactuation in their internal shape, such as soft robots. This thesis will cover these findings and results, simulated and physical, and the surprising practicality of data-driven geometric mechanics.PHDRoboticsUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/168033/1/babitt_1.pd

Nature inspired surface/interface engineering towards advanced device applications

Nature inspired surface/interface with multi-faceted functions possess promises in the frontier engineering applications in flexible electronics, energy harvesting, autonomous systems, bio-mimicking tissues, micro-fluidics, etc. Understanding the relationship between nature’s architecture and underlying science could bring enabling solutions to overcome the engineering challenges. A nature inspired surface with smart resilient features provides intrinsic complexity and their multiplicity under different stimuli, i.e. chemical, physical, electronic, mechanical and (in some cases) biological properties. By mimicking/harvesting a variety of surface and interfacial features from nature, the final composition will display an integrative design to provide further explorations in deciphering the hidden physics towards advanced device applications in real world. Specifically, we bring a few engineering examples with chemical/physical approaches to construct artificial nano/micro-structured surface, yield various functional surface for different application scenarios. • A porous layer has been realised to provide controllable generation of microarchitecture to exhibit an anti-corrosion behaviour under UV exposure with multifaceted characteristics such as profound solar absorptivity, thermal emissivity. By further treating the surface with silane, a hybrid layer has been established with superhydrophobic and anti-icing features which shares innate interests in thermal transport/aero-space engineering. • The structural conformation/ elastic instabilities of the surface are exploited to devise an extreme switchable configuration to develop a morphing strategy for switchable lipophilic/oleophobic properties. The geometrical shift of soft structure is instructed to create a steady transition of surface topology rendering a unique switchable transition that are widely inspired in sub-sea/offshore engineering for oil and water separation. • We also develop a highly-replenishable thermal energy harvesting technology via a dynamical elasto-bouncing process of polymeric hydrogel to translate the thermal energy into useful elasto-kinetic energy, then further converted into electrical energy via a simple piezo-material based system, which paves way for a future portable and conformable energy harvesting tool in the regions of extreme geo-thermal residencies and industries. • Using a one drop filling technique along with interfacial pinning points between hydrophilic and hydrophobic, a unique microfluidic approach is presented to create heterogenous structures. By exploiting the communication between swelling mismatch of different functional groups, driven via in-plane and through thickness heterogeity, a highly complex 3D soft reconfiguration is achieved which is activated by stimulation inputs. • The theoretical understandings are exploited in the above applied engineering scenarios, such as elastic mechanics, morphing structure, surface/interface interactions and kinetics of of the polymer systems experienced on a hot surface, which offers further insights into the elastic recoiling evolution and tunability of the system for effective energy translation efficiency. We hope above approaches shed more lights on the nature inspired structure in device engineering, thus, advance the knowledge in the frontier science

15th Conference on Dynamical Systems Theory and Applications DSTA 2019 ABSTRACTS

From Preface: This is the fifteen time when the conference „Dynamical Systems – Theory and Applications” gathers a numerous group of outstanding scientists and engineers, who deal with widely understood problems of theoretical and applied dynamics. Organization of the conference would not have been possible without a great effort of the staff of the Department of Automation, Biomechanics and Mechatronics. The patronage over the conference has been taken by the Committee of Mechanics of the Polish Academy of Sciences and the Ministry of Science and Higher Education. It is a great pleasure that our invitation has been accepted by so many people, including good colleagues and friends as well as a large group of researchers and scientists, who decided to participate in the conference for the first time. With proud and satisfaction we welcome nearly 255 persons from 47 countries all over the world. They decided to share the results of their research and many years experiences in the discipline of dynamical systems by submitting many very interesting papers. This booklet contains a collection of 338 abstracts, which have gained the acceptance of referees and have been qualified for publication in the conference edited books.Technical editor and cover design: Kaźmierczak, MarekCover design: Ogińska, Ewelina; Kaźmierczak, Mare

Rat hind limb nociceptive withdrawal response to heat and mechanical stimuli depends on initial position of the paw but not stimulus location

Mammals rapidly withdraw their hind limb in response to noxious stimulation, which is a protective movement known as the nociceptive withdrawal response (NWR). The NWR has been previously studied in spinalized, decerebrated and anesthetized non-human and human mammals; however, there is minimal information on the NWR in intact, unanesthetized non-human mammals. The first specific aim was to identify the factors that determine the direction and magnitude of the NWR in intact, unanesthetized rats. Based on previous studies, we hypothesized that the location of stimulation and the initial position of the paw preceding the NWR will influence the direction and magnitude of the NWR. Rats were mechanically stimulated (“Von Frey” monofilament or 30-gauge needle) at five spots widely distributed over the plantar surface of the hind, left paw. In response to heat or mechanical stimulation to the plantar surface of the paw, rats withdraw and then replace the stimulated paw on the surface. The NWR was quantified as the vector between the initial and final positions of the stimulated paw. Unexpectedly, stimulus location did not significantly influence the direction of the response, falsifying our hypothesis. However, the initial position of paw was variable, suggesting an influence on the direction of response. Correlation between the initial position and the change in position rostral/caudally and lateral/medially revealed a significant and inverse effect on response direction. Thus, if the paw was initially rostral, it would move caudal after stimulation; if the paw was initially caudal, it would move rostral. Second, after determining that the direction of the NWR depended on the initial position of the paw, we tested whether the rat used proprioceptive sensory feedback or corollary discharge to identify the position of the paw prior to stimulation. Based on previous studies, we hypothesized that proprioceptive sensory feedback, rather than corollary discharge, would underlie the dependence on initial paw position. Rats were stimulated by heat with an infrared laser to a single region of the paw, which was placed on an independently movable glass plate. The plate was repositioned rostral-caudally (forward-backward) just before evoking the NWR to dissociate proprioceptive sensory feedback from corollary discharge. The NWR was unaffected by repositioning the paw prior to the evoking the NWR, consistent with proprioceptive sensory feedback being used by the rat to determine the direction and magnitude of the NWR. Taken together, our results suggest the central nervous system in intact rats primarily uses proprioceptive information about limb posture, but not stimulus location, to determine the direction of the NWR movement. Thus, the NWR appears designed to both maintain posture, as well as protect the paw from injury. Since the NWR is the most widely used clinical test of reflexes, our results may enable improved understanding, diagnosis and treatment of neurological diseases and trauma