Design Issues for Hexapod Walking Robots

Hexapod walking robots have attracted considerable attention for several decades. Many studies have been carried out in research centers, universities and industries. However, only in the recent past have efficient walking machines been conceived, designed and built with performances that can be suitable for practical applications. This paper gives an overview of the state of the art on hexapod walking robots by referring both to the early design solutions and the most recent achievements. Careful attention is given to the main design issues and constraints that influence the technical feasibility and operation performance. A design procedure is outlined in order to systematically design a hexapod walking robot. In particular, the proposed design procedure takes into account the main features, such as mechanical structure and leg configuration, actuating and driving systems, payload, motion conditions, and walking gait. A case study is described in order to show the effectiveness and feasibility of the proposed design procedure

Bio-Inspired Robotics

Modern robotic technologies have enabled robots to operate in a variety of unstructured and dynamically-changing environments, in addition to traditional structured environments. Robots have, thus, become an important element in our everyday lives. One key approach to develop such intelligent and autonomous robots is to draw inspiration from biological systems. Biological structure, mechanisms, and underlying principles have the potential to provide new ideas to support the improvement of conventional robotic designs and control. Such biological principles usually originate from animal or even plant models, for robots, which can sense, think, walk, swim, crawl, jump or even fly. Thus, it is believed that these bio-inspired methods are becoming increasingly important in the face of complex applications. Bio-inspired robotics is leading to the study of innovative structures and computing with sensory–motor coordination and learning to achieve intelligence, flexibility, stability, and adaptation for emergent robotic applications, such as manipulation, learning, and control. This Special Issue invites original papers of innovative ideas and concepts, new discoveries and improvements, and novel applications and business models relevant to the selected topics of ``Bio-Inspired Robotics''. Bio-Inspired Robotics is a broad topic and an ongoing expanding field. This Special Issue collates 30 papers that address some of the important challenges and opportunities in this broad and expanding field

Enhancing Innovation Through Biologically Inspired Design

Mixing upper level undergraduates majoring in engineering with those majoring in biology, we have devised a course on biologically-inspired design (BID) that provides practical training in methods and techniques that facilitate the identification and translation of biological principles into solutions for human challenges. The challenges of interdisciplinary courses generally, and the specific challenges of fostering exchange among biologists and engineers lead us to define these learning goals: (1) basic knowledge of successful examples of BID, (2) interdisciplinary communication skills, (3) knowledge about domains outside of their core training, (4) a uniquely interdisciplinary design process, and (5) how to apply existing technical knowledge to a new discipline. We developed the following course components to meet the key learning objectives: BID Lectures; Design Lectures; Found object exercises; Quantitative assessments; Analogy exercises; Research assignments; Interdisciplinary Collaboration, Mentorship; Idea Journals and Reflections. We will provide an extensive description of these elements, which we have chosen to incorporate based on our own experience with interdisciplinary communication, as well as findings from cognitive science regarding how students actually learn. This 15 week course is organized using assignments of increasing complexity that allow students to learn and apply essential skills of BID methodology and practice. Early exercises, which combine lectures, group discussions and individual assignments, have these objectives: 1) allow students to develop the necessary inter-disciplinary communication and research skills to facilitate their design project work; 2) expose students to ideation and design skills that will encourage them to work outside of their comfort zone; 3) practice the analogical reasoning skills that facilitate the successful search for and application of relevant biological concepts. This initial portion of the course stresses that BID occurs at the early phase of a design process and that identifying solutions from the biological domain requires that students have a sufficient breakdown of their problem combined with sufficient biological knowledge to suggest appropriate mappings between problem and solution. Two primary barriers are a lack of appreciation for how the evolutionary “design” process differs from human design, and the use of different terminology for describing similar processes in biology vs. engineering. We describe some teaching practices and activities that allow students to overcome these difficulties. The course culminates in a group project, which is a detailed conceptual design including a preliminary analysis of expected performance, value, and feasibility. A unique feature of the course is that it represents the efforts of not only biologists and engineers, but also contributions from cognitive scientists engaged in understanding human cognition and creativity. Our course strategy has been deeply influenced by findings in that field. We have studied the activity of classroom participants for the last three years, examining the processes they use, and intermediate and final design representations. Analysis of this has yielded a number of observations about the cognitive process of biologically inspired design that may provide insights regarding how to enhance BID education, as well as provide useful insight for professionals in the design field. Key words: biologically-inspired design (BID); interdisciplinary communicatio

Doctor of Philosophy

dissertationPhosphate-metal complex formation is a naturally occurring toughening mechanism in underwater materials and has been incorporated into the synthetic hydrogel material discussed in this dissertation. Polyphosphate hydrogels were loaded with Ca2+ which crosslinks OPO3 groups in the hydrogel which increase the initial modulus from 0.04 to 10.3 MPa and rupture at a critical force to dissipate strain energy and act as a sacrificial network to preserve the integrity of the hydrogel. Phosphate metal crosslinks are electrostatic domains that are easily recoverable, which adds to the durability and usefulness of the hydrogels. This toughening mechanism was borrowed from the underwater caddisfly larvae, which spin a tough, adhesive silk fiber to manufacture protective mobile cases from sticks, rocks and other advantageously gathered materials. The caddisfly silk also uses serial domains of phosphates crosslinked with Ca2+ to increase modulus and produce strain induced yield, energy dissipation, and recoverability. In addition to metal ions, positively charged aminoglycoside antibiotics such as tobramycin can also be used as crosslinking agents. Due to electrostatically delayed diffusion, tobramycin is gradually released and exchanged with metal ions in biologically relevant Ca2+ and Mg2+ containing solutions. In the polyphosphate hydrogel system, tobramycin was included with and without the presence of Ca2+ to form a hydrogel with the capability to sustain tobramycin release for up to 70 days and totally eradicate pseudomonas aeruginosa biofilms within 48 hours. In the case of hydrogels loaded with Ca2+ and tobramycin, the hydrogels retained their toughness, and durability and thus may be used as structural materials in total joint replacement to reduce incidence of infection. Complex coacervation is an alternative to the polyphosphate-tobramycin hydrogel system and occurs as a phase separation where a dense coacervate of polyphosphate and tobramycin is formed. The formation of clear, fluid coacervate phase is dependent on salt concentration and is maximized at ~1M NaCl. Polyphosphate-tobramycin coacervates have a sustained release assay for up to 60 days. Additionally, the coacervate can be resuspended into micro droplets by vortex and subsequently aerosolized for pulmonary delivery of tobramycin. Aerosolized coacervate is ideal for treating chronic pulmonary infection in cystic fibrosis. It could not only improve rates of pseudomonas aeruginosa infection but also reduce the number of required doses and thus improve patient compliance

Ocean forests: breakthrough yields for macroalgae

The US Department of Energy Advanced Research Projects Agency - Energy (ARPA-E) MacroAlgae Research Inspiring Novel Energy Research (MARINER) program is encouraging technologies for the sustainable harvest of large funding research of macroalgae for biofuels at less than $80 per dry metric ton (DMT). The Ocean Forests team, led by the University of Southern Mississippi, is developing a complete managed ecosystem where nutrients are transformed and recycled. The team’s designs address major bottlenecks in profitability of offshore aquaculture systems including economical moored structures that can withstand storms, efficient planting, managing and harvesting systems, and sustainable nutrient supply. The work is inspired by Lapointe who reported yields of Gracilaria tikvahiae equivalent to 127 DMT per hectare per year (compared with standard aquaculture systems in the range of 20 to 40 DMT/ha/yr). This approach offers the potential for breakthrough yields for many macroalgae species. Moreover, mini-ecosystems in offshore waters create communities of macroalgae, shellfish, and penned finfish, supplemented by visiting free-range fish that can increase productivity, produce quality products, and create jobs and income for aquafarmers. Additional benefits include reduced disease in fish pens, cleaning contaminated coastal waters, and maximizing nutrient recycling. Cost projections for a successful, intensive, scaled system are competitive with current prices for fossil fuels

Fluid mechanics of bubble capture by the diving bell spider

Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2010.Cataloged from PDF version of thesis.Includes bibliographical references (p. 55-56).The water spider, a unique member of its species, is used as inspiration for a bubble capture mechanism. Bubble mechanics are studied in the pursuit of a biomimetic solution for transporting air bubbles underwater. Careful experimentation is performed to understand the mechanics of bubble formation and capture. Investigation of bubble formation through an underwater nozzle shows that bubble volume increases by 15% when parallel rods are spaced above the nozzle at the same width as the inner diameter of the nozzle. Bubble volume decreases linearly with increasing air injection rate. Decreasing surface tension by approximately 40% decreases bubble volume by approximately 20%. Changing the angle the nozzle from parallel to perpendicular with the bottom of the tank increases bubble volume 40%. Based on trends observed in the nozzle experiments and using the spider's mechanisms for bubble capture as inspiration, a bubble capture device is manufactured. Decreasing the surface tension of the fluid by 25% decreases captured bubble volume by 50%. Below a device submersion speed of approximately 2.4 mm/s, bubble formation was at a maximum for the device, regardless of fluid surface tension. This research elucidates the limitations on bubble capture by the water spider. For future applications, these limitations can be pinpointed and adjusted for more efficient bubble capture and plastron maintenance.by Alice Brooks.S.B

Dancing and Poetry: A Study of the Whirling Dervish Dance Through Rumi’s Poetry

This exploration investigates the influence of Rumi’s book of poetry, Mathnawi, upon the Sufi practice of the Whirling Dervish dances. It argues that Rumi’s Mathnawi underlies the choreography of the Whirling Dervish dances. Each step of the dance expresses, manifests or embodies themes found in Rumi’s poetry: separation from Unity, ascension, annihilation, and a return to Unity. The thesis introduces this argument, and then discusses historical, theological, and linguistic themes related to Rumi, Sufism, and the Whirling Dervish dances. Following this, the thesis provides a framework that begins with the Neoplatonic theory of emanation grounding Rumi’s poetic thought, followed by the influence of Rumi’s poetic thought upon the Whirling Dervish dances. The thesis then uses this framework to explore each step of the Whirling Dervish dance individually as it relates to poems within Mathnawi, examining the relationship between poetry and choreography. Four poems have been selected, correlating with the four steps of the dance. The poems are analytically dissected and evaluated. In conclusion, this thesis demonstrates how Mathnawi choreographically serves as a guide and structure for the Whirling Dervish practice, in addition to broadly demonstrating the influence of Rumi’s poetic thought upon future generations of religious Sufi practice

Marine Gastrobot Final Design Report

The Marine Gastrobot sponsored by Dr. Christopher Kitts of the Cal Poly Center for Applications in Biotechnology was a research and development effort intended to explore the use of microbial fuel cell technology as a power source for underwater robots. Our team Ocean Locomotion succeeded in developing a first iteration of an underwater robotic platform suitable for microbial fuel cell integration. The primary feature of the design is its sinusoidal fin propulsion intended for benthic exploration with limited risk of entanglement. During the course of development, Ocean Locomotion explored the use of low power actuation methods and determined their limited use for underwater locomotion, tested low power boost converter compatibility with microbial fuel cells, and built hardware capable of integration with microbial fuel cells