Biomimetic leg design and passive dynamics of Dolomedes aquaticus

Spiders provide working models for agile, efficient miniature passive-dynamic robots. Joints are extended by haemoplymph (hydraulic) pressure and flexed by muscle-tendon systems. Muscle contraction in the prosoma leads to an increase in hydraulic pressure and subsequently leg extension. Analysis of body kinematics the New Zealand fishing spider, Dolomedes aquaticus indicates that elastic plates around the joints absorb energy from the ground reaction force when the force vector points backwards (i.e. would decelerate the spider’s body in the direction of locomotion) and release it to provide forward thrust as the leg swings backwards. In addition to improving energy efficiency, this mechanism improves stability by passively absorbing energy from unpredictable foot-ground impacts during locomotion on uneven terrain. These principles guided an iterative design methodology using a combination of 3D modelling software and 3D printing techniques. I compared and contrasted compliant joints made of a variety of plastic materials. The final 3D-printed spider leg prototype has a stiff ABS exoskeleton joined by a compliant polypropylene backbone. The entire structure envelopes a soft silicone pneumatic bladder. FEA analysis was used to determine the ideal shape and behavior of the pneumatic bladder to actuate the exoskeleton. The spider leg can be flexed and contracted depending on the input pressure. To laterally actuate this pneumatic spider leg I designed and developed a fabrication system that uses vacuum injection molding to produce an integrated mesh sleeve/elastomer pneumatic actuator. I designed an apparatus to measure pressure and contraction of silicone and latex pneumatic muscles when inflated. I analyzed the non-linear pressure-contraction relationships of silicone versus latex pneumatic muscles, and also derived force-contraction relationships. From efficiency studies, both media muscles proved to be inefficient and the measuring apparatus needs to be more robust to prevent leaking air. The fabrication process still offers the possibility of a quick and efficient method of creating pneumatic muscles. A spider-like robot that implements these pneumatic muscles and pneumatic leg design could be used to explore the efficiency and stability of passive dynamic legged locomotion in spider-like robots

Insect inspired visual motion sensing and flying robots

International audienceFlying insects excellently master visual motion sensing techniques. They use dedicated motion processing circuits at a low energy and computational costs. Thanks to observations obtained on insect visual guidance, we developed visual motion sensors and bio-inspired autopilots dedicated to flying robots. Optic flow-based visuomotor control systems have been implemented on an increasingly large number of sighted autonomous robots. In this chapter, we present how we designed and constructed local motion sensors and how we implemented bio-inspired visual guidance scheme on-board several micro-aerial vehicles. An hyperacurate sensor in which retinal micro-scanning movements are performed via a small piezo-bender actuator was mounted onto a miniature aerial robot. The OSCAR II robot is able to track a moving target accurately by exploiting the microscan-ning movement imposed to its eye's retina. We also present two interdependent control schemes driving the eye in robot angular position and the robot's body angular position with respect to a visual target but without any knowledge of the robot's orientation in the global frame. This "steering-by-gazing" control strategy, which is implemented on this lightweight (100 g) miniature sighted aerial robot, demonstrates the effectiveness of this biomimetic visual/inertial heading control strategy

Autopoietic-extended architecture: can buildings think?

To incorporate bioremedial functions into the performance of buildings and to balance generative architecture's dominant focus on computational programming and digital fabrication, this thesis first hybridizes theories of autopoiesis into extended cognition in order to research biological domains that include synthetic biology and biocomputation. Under the rubric of living technology I survey multidisciplinary fields to gather perspective for student design of bioremedial and/or metabolic components in generative architecture where generative not only denotes the use of computation but also includes biochemical, biomechanical, and metabolic functions. I trace computation and digital simulations back to Alan Turing's early 1950s Morphogenetic drawings, reaction-diffusion algorithms, and pioneering artificial intelligence (AI) in order to establish generative architecture's point of origin. I ask provocatively: Can buildings think? as a question echoing Turing's own "Can machines think?" Thereafter, I anticipate not only future bioperformative materials but also theories capable of underpinning strains of metabolic intelligences made possible via AI, synthetic biology, and living technology. I do not imply that metabolic architectural intelligence will be like human cognition. I suggest, rather, that new research and pedagogies involving the intelligence of bacteria, plants, synthetic biology, and algorithms define approaches that generative architecture should take in order to source new forms of autonomous life that will be deployable as corrective environmental interfaces. I call the research protocol autopoietic-extended design, theorizing it as an operating system (OS), a research methodology, and an app schematic for design studios and distance learning that makes use of in-field, e-, and m-learning technologies. A quest of this complexity requires scaffolding for coordinating theory-driven teaching with practice-oriented learning. Accordingly, I fuse Maturana and Varela's biological autopoiesis and its definitions of minimal biological life with Andy Clark's hypothesis of extended cognition and its cognition-to-environment linkages. I articulate a generative design strategy and student research method explained via architectural history interpreted from Louis Sullivan's 1924 pedagogical drawing system, Le Corbusier's Modernist pronouncements, and Greg Lynn's Animate Form. Thus, autopoietic-extended design organizes thinking about the generation of ideas for design prior to computational production and fabrication, necessitating a fresh relationship between nature/science/technology and design cognition. To systematize such a program requires the avoidance of simple binaries (mind/body, mind/nature) as well as the stationing of tool making, technology, and architecture within the ream of nature. Hence, I argue, in relation to extended phenotypes, plant-neurobiology, and recent genetic research: Consequently, autopoietic-extended design advances design protocols grounded in morphology, anatomy, cognition, biology, and technology in order to appropriate metabolic and intelligent properties for sensory/response duty in buildings. At m-learning levels smartphones, social media, and design apps source data from nature for students to mediate on-site research by extending 3D pedagogical reach into new university design programs. I intend the creation of a dialectical investigation of animal/human architecture and computational history augmented by theory relevant to current algorithmic design and fablab production. The autopoietic-extended design dialectic sets out ways to articulate opposition/differences outside the Cartesian either/or philosophy in order to prototype metabolic architecture, while dialectically maintaining: Buildings can think

An analysis of the locomotory behaviour and functional morphology of errant polychaetes

EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Biological adhesion in wet environments: adaptations and mechanisms

Physiochemical conditions in water are fundamentally different to those in air; hence, organisms require special adaptations to adhere in wet environments. In my thesis, I have investigated three study systems to elucidate mechanisms for adhesion under wet conditions. In Chapters 2 and 3, I explore an aquatic insect (Diptera: Blephariceridae) that uses suction organs to attach to rocks in raging alpine torrents. Suction-based attachment is driven by physical processes requiring a pressure difference and a seal to maintain it. Through my investigations, I have identified several key principles for biological suction attachments to wet and rough surfaces. Using three-dimensional reconstructions of blepharicerid suction organs and in vivo visualisation of the adhesive contact zone, I found several internal and external morphological adaptations that are important for strong adhesion under water. Moreover, I characterised a mechanism for rapid detachment which is the first detailed account of an actively controlled detachment system in biological suction organs. In Chapter 4, I investigate the contribution of physical and chemical mechanisms to the powerful attachment of common limpets (Patella vulgata) to rocks in the intertidal zone. I demonstrate that suction is not the primary contributor to their attachment forces; rather, it is their adhesive pedal mucus that is responsible. This adhesive mucus comprises of a complex mixture of glycans and proteins, many of which share homology with adhesive secretions from other marine invertebrates, such as sea stars, sea anemones, and flatworms. In Chapters 5 and 6, I study the physical and chemical properties of sticky secretions from carnivorous pitcher plants (Nepenthes) that help to capture, retain, and digest insects. I show that the viscoelastic pitcher fluid readily adheres to but not easily dewets from insect cuticle, and forms stable filaments as the insect attempts to escape that require significant work to overcome. In addition, the surface tension is reduced in pitcher fluid compared to water, making insects sink more easily into the former and facilitating further wetting of the cuticle. Chemical characterisation of the pitcher fluid revealed that its sticky filamentous property is caused by a polysaccharide with a glucurono-mannan backbone structure, which is chemically stable and contains carboxylic groups for strong interactions. Glucurono-mannan are an understudied group of plant polysaccharides that are present in mucilaginous secretions from across the plant kingdom, including sticky capture fluids from other carnivorous plants. My findings show that pitcher plant fluid can be used as a study system for future investigations into the origins and functional role of glucurono-mannan in carnivorous plants. In summary, my thesis has identified novel adaptations and principles for biological adhesion under wet conditions using three selected study systems, hence expanding our understanding of the underlying physical and chemical mechanisms and providing inspiration for biomimetic adhesives with improved performance in wet environments.EU Horizon 2020 under Marie Skłodowska-Curie grant agreement No. 64286

29th Annual Computational Neuroscience Meeting: CNS*2020

Meeting abstracts This publication was funded by OCNS. The Supplement Editors declare that they have no competing interests. Virtual | 18-22 July 202