an efficient soil penetration strategy for explorative robots inspired by plant root circumnutation movements

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Bio-inspired geotechnical engineering: principles, current work, opportunities and challenges

A broad diversity of biological organisms and systems interact with soil in ways that facilitate their growth and survival. These interactions are made possible by strategies that enable organisms to accomplish functions that can be analogous to those required in geotechnical engineering systems. Examples include anchorage in soft and weak ground, penetration into hard and stiff subsurface materials and movement in loose sand. Since the biological strategies have been ‘vetted’ by the process of natural selection, and the functions they accomplish are governed by the same physical laws in both the natural and engineered environments, they represent a unique source of principles and design ideas for addressing geotechnical challenges. Prior to implementation as engineering solutions, however, the differences in spatial and temporal scales and material properties between the biological environment and engineered system must be addressed. Current bio-inspired geotechnics research is addressing topics such as soil excavation and penetration, soil–structure interface shearing, load transfer between foundation and anchorage elements and soils, and mass and thermal transport, having gained inspiration from organisms such as worms, clams, ants, termites, fish, snakes and plant roots. This work highlights the potential benefits to both geotechnical engineering through new or improved solutions and biology through understanding of mechanisms as a result of cross-disciplinary interactions and collaborations

Bio-inspired geotechnical engineering: Principles, current work, opportunities and challenges

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Mathematical models for biological motility: From peristaltic crawling to plant nutations

In this thesis we propose mathematical models for the motility of one-dimensional crawlers moving along a line and for growing slender plant organs, which are applied to the study of peristaltic crawling and nutations of plant shoots, respectively. The first chapter contains a theoretical analysis of metameric worm-like robotic crawlers, and it investigates optimal actuation strategies. Our main result is that peristalsis, i.e., muscle extension and contraction waves propagating along the body, is an optimal actuation strategy for locomotion. We give a rigorous mathematical proof of this result by solving analytically the optimal control problem in the regime of small deformations. We show that phase coordination arises from the geometric symmetry of a 1D system, exactly in the periodic case and approximately, due to edge-effects, in the case of a crawler of finite length. In the second chapter we introduce the general framework of morphoelastic rods to model elongating slender plant organs. This chapter is intended as preparatory to the third one, where we derive a rod model that is exploited to investigate the role of mechanical deformations in circumnutating plant shoots. We show that, in the absence of endogenous cues, spontaneous oscillations might arise as system instabilities when a loading parameter exceeds a critical value. Moreover, when oscillations of endogenous nature are present, their relative importance with respect to the ones associated with the former mechanism varies in time, as the biomechanical properties of the shoot change. Our findings suggest that the relative importance of exogenous versus endogenous oscillations is an emergent property of the system, and that elastic deformations play a crucial role in this kind of phenomena

Toward Growing Robots: A Historical Evolution from Cellular to Plant-Inspired Robotics

This paper provides the very first definition of "growing robots": a category of robots that imitates biological growth by the incremental addition of material. Although this nomenclature is quite new, the concept of morphological evolution, which is behind growth, has been extensively addressed in engineering and robotics. In fact, the idea of reproducing processes that belong to living systems has always attracted scientists and engineers. The creation of systems that adapt reliably and effectively to the environment with their morphology and control would be beneficial for many different applications, including terrestrial and space exploration or the monitoring of disasters or dangerous environments. Different approaches have been proposed over the years for solving the morphological adaptation of artificial systems, e.g., self-assembly, self-reconfigurability, evolution of virtual creatures, plant inspiration. This work reviews the main milestones in relation to growing robots, starting from the original concept of a self-replicating automaton to the achievements obtained by plant inspiration, which provided an alternative solution to the challenges of creating robots with self-building capabilities. A selection of robots representative of growth functioning is also discussed, grouped by the natural element used as model: molecule, cell, or organism growth-inspired robots. Finally, the historical evolution of growing robots is outlined together with a discussion of the future challenges toward solutions that more faithfully can represent biological growth

Novel Vine-like Continuum Robot for Environmental Exploration Applications

This thesis details a new design and novel operational strategies for nature inspired, thin tendril continuum robots. Instead of taking inspiration for robot design from insects or animals, the novel approach to continuum robotics herein takes inspiration and adapts operational concepts from plant life. In particular, an innovative strategy is developed which mimics behaviors observed in vines and other climbing plants. Specifically, a tendril robot with prickles was developed and deployed to actively seek environmental contact, exploiting the mechanical advantage gained by bracing against the environment using the prickles. The resulting performance enhancements over previously developed smooth backbone tendril robot designs, and use of strategies that do not attempt to interact with the environment are empirically demonstrated with the new robot prototype. Results of further experiments suggest applications in which the new design and approach could prove useful to the scientific and wider communities

Aerospace Medicine and Biology: A continuing bibliography with indexes, supplement 187

This supplement to Aerospace Medicine and Biology lists 247 reports, articles and other documents announced during November 1978 in Scientific and Technical Aerospace Reports (STAR) or in International Aerospace Abstracts (IAA). In its subject coverage, Aerospace Medicine and Biology concentrates on the biological, physiological, psychological, and environmental effects to which man is subjected during and following simulated or actual flight in the earth's atmosphere or in interplanetary space. References describing similar effects of biological organisms of lower order are also included. Emphasis is placed on applied research, but reference to fundamental studies and theoretical principles related to experimental development also qualify for inclusion. Each entry in the bibliography consists of a bibliographic citation accompanied in most cases by an abstract

Aerospace medicine and biology: A continuing bibliography with indexes (supplement 365)

This bibliography lists 211 reports, articles and other documents introduced into the NASA Scientific and Technical Information System during July 1992. Subject coverage includes: aerospace medicine and physiology, life support systems and man/system technology, protective clothing, exobiology and extraterrestrial life, planetary biology, and flight crew behavior and performance