Download or read book A Study of Shape Memory Alloy Wires as Actuators for Textile Robotics and Compression Garment Applications written by Jamie L. Kennedy and published by . This book was released on 2016 with total page 398 pages. Available in PDF, EPUB and Kindle. Book excerpt: In 2008, a Surgeon General's Call to Action was published on how to prevent Deep Vein Thrombosis, DVT, and Pulmonary Embolism, PE. These two diseases are the main cause blood clots and hold high death counts. With the only prevention devices being two extremes, a static compression garment and a pneumatic compression boot with a non-movable air pump, hospital-level care is not available in a transportable, comfortable and cost-effective system. If a textile soft-robotic device could be introduced to the employment of blood clot prevention, a medium ground could be accomplished where a patient can obtain hospital-level quality care anywhere with higher comfort. To achieve this goal, textile-based robotics have been considered with the implementation of smart materials into knitted and woven fabrics. This thesis studies and utilizes shape memory alloys, SMAs, as a smart material inside of a woven textile for an outcome of a robotically-controllable fabric. SMAs are a unique material that can transform into a trained or "memorized'' shape when a thermal condition is met. This, along with many super-elastic material properties, including high power and force-to-weight ratios, makes SMAs remarkable for actuation in robotics. SMA integration into fabrics brings a new outcome of functioning fabric-structures through thermal control. However, most SMA research is within the linear scope of actuation due to a hysteresis in the material, as well as the lack of natural recovery and control over the actuation path. This work characterizes bending-force outcomes of SMA actuators within woven structures to develop a massaging sleeve or sock to prevent DVT and PE. Currently, the field of SMA-fabric integration is limited with the research focused on aesthetic and commercial needs. This work will strive to focus on the robotic, medical, and industrial aspects of the integration through the development of a woven SMA-fabric massaging structure. Specific SMA working parameters are experimentally researched and modeled for both linear and bending actuators. These parameters include transformation temperature, power consumption, acceleration, torque and angular displacement. These parameters are controlled through material properties, the annealing process and the actuation parameters of the SMA wire segments. The main outcomes of this research are a bending force study of 60 mm SMA wire segments by themselves and within a woven textile. Proof of concepts of the textile-based robot and compression garment applications are carried out and compared with current implementations and SMA actuators in this field. The progression has the potential to be implemented in the development of a fully woven massaging sock or sleeve to prevent blood clots.
Download or read book Shape Memory Alloys Muscle Wires and Robotics written by Antonio Flores-Galea and published by Createspace Independent Publishing Platform. This book was released on 2016-05-26 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Muscle wires, nitinol, Flexinol or -formally called- shape-memory alloys (SMA) present a huge demand today because of their high power/weight ratio. That means that, when combined with cheap, light-weighted batteries available in the market, they are the best choice for mobile robotics.This book is a thorough study of the state of the art about how this technology is used in robotics. It provides a full overview of the concepts as well as practical examples of implementation that can be performed in a university laboratory.The author, Benjamin C. Lawson, has focused on writing a book that comprises all the basic knowledge available about the technology, with an accessible and easy-to-read book, valid for students, professors, professional and even amateurs of robotics.
Download or read book Thermal Modeling of Shape Memory Alloy Wire Actuators for Automotive Applications written by Huilong Ma and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Shape Memory Alloy Actuators written by Burcu Dönmez and published by . This book was released on 2011-11 with total page 216 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book THERMOMECHANICAL CHARACTERIZATION OF ONE WAY SHAPE MEMORY NITINOL AS AN ACTUATOR FOR ACTIVE SURGICAL NEEDLE written by Mohammad Honarvar and published by . This book was released on 2014 with total page 104 pages. Available in PDF, EPUB and Kindle. Book excerpt: Needle-based intervention insertion is one of the common surgical techniques used in many diagnostic and therapeutic percutaneous procedures. The success of such procedures highly depends on the accuracy of needle placement at target locations. An active needle has the potential to enhance the accuracy of needle placement as well as to improve clinical outcome. Bending forces provided by the attached actuators can assist the maneuverability in order to reach the targets following a desired trajectory. There are three major research parts in the development of active needle project in the Composites Laboratory of Temple University. They are thermomechanical characterization of shape memory alloy (SMA) or Nitinol as an actuator for smart needle, mechanical modeling and design of smart needles, and study of tissue needle interaction. The characterization of SMA is the focus of this dissertation. Unique thermomechanical properties of Nitinol known as shape memory effect and superelasticity make it applicable for different fields such as biomedical, structural and aerospace engineering. These unique behaviors are due to the comparatively large amount of recoverable strain which is being produced in a martensitic phase transformation. However, under certain ranges of stresses and temperatures, Nitinol wires exhibit unrecovered strain (also known as residual strain); which limits their applicability. Therefore, for applications that rely on the strain response in repetitive loading and unloading cycles, it is important to understand the generation of the unrecovered strain in the Nitinol wires. In this study, the unrecovered strain of Nitinol wires with various diameters was investigated, using two experimental approaches: constant stress and uniaxial tensile tests. Moreover, a critical range of stress was found beyond which the unrecovered strain was negligible at temperatures of 70 to 80C depending on the wire diameter. Wire diameters varied from 0.10 to 0.29 mm were tested and different ranges of critical stress were found for different wire diameters. The transformation temperatures of different wire diameters at zero stress have been achieved by performing the Differential Scanning Calorimetry (DSC) test. The actuation force created by Nitinol wire is measured through constant strain experiment. X-Ray Diffraction (XRD) study was also performed to investigate the phase of Nitinol wires under various thermomechanical loading conditions. In summary, the effect of wire diameter on the required critical stresses to avoid the unrecovered strain between first and second cycle of heating and cooling are presented and the results of both mechanical tests are justified by the results obtained from the XRD study.
Download or read book Principles of Animal Locomotion written by R. McNeill Alexander and published by Princeton University Press. This book was released on 2006-03-19 with total page 384 pages. Available in PDF, EPUB and Kindle. Book excerpt: How can geckoes walk on the ceiling and basilisk lizards run over water? What are the aerodynamic effects that enable small insects to fly? What are the relative merits of squids' jet-propelled swimming and fishes' tail-powered swimming? Why do horses change gait as they increase speed? What determines our own vertical leap? Recent technical advances have greatly increased researchers' ability to answer these questions with certainty and in detail. This text provides an up-to-date overview of how animals run, walk, jump, crawl, swim, soar, hover, and fly. Excluding only the tiny creatures that use cilia, it covers all animals that power their movements with muscle--from roundworms to whales, clams to elephants, and gnats to albatrosses. The introduction sets out the general rules governing all modes of animal locomotion and considers the performance criteria--such as speed, endurance, and economy--that have shaped their selection. It introduces energetics and optimality as basic principles. The text then tackles each of the major modes by which animals move on land, in water, and through air. It explains the mechanisms involved and the physical and biological forces shaping those mechanisms, paying particular attention to energy costs. Focusing on general principles but extensively discussing a wide variety of individual cases, this is a superb synthesis of current knowledge about animal locomotion. It will be enormously useful to advanced undergraduates, graduate students, and a range of professional biologists, physicists, and engineers.
Download or read book Textiles Identity and Innovation Design the Future written by Gianni Montagna and published by CRC Press. This book was released on 2018-10-03 with total page 454 pages. Available in PDF, EPUB and Kindle. Book excerpt: D_TEX presents itself as a starting point at a crossroads of ideas and debates around the complex universe of Textile Design in all its forms, manifestations and dimensions. The textile universe, allied to mankind since its beginnings, is increasingly far from being an area of exhausted possibilities, each moment proposing important innovations that need a presentation, discussion and maturation space that is comprehensive and above all inter- and transdisciplinary. Presently, the disciplinary areas where the textile area is present are increasing and important, such as fashion, home textiles, technical clothing and accessories, but also construction and health, among others, and can provide new possibilities and different disciplinary areas and allowing the production of new knowledge. D_TEX proposes to join the thinking of design, with technologies, tradition, techniques, and related areas, in a single space where ideas are combined with the technique and with the projectual and research capacity, thus providing for the creation of concepts, opinions, associations of ideas, links and connections that allow the conception of ideas, products and services. The interdisciplinary nature of design is a reality that fully reaches the textile material in its essence and its practical application, through the synergy and contamination by the different interventions that make up the multidisciplinary teams of research. The generic theme of D_TEX Textile Design Conference 2017, held at Lisbon School of Architecture of the University of Lisbon, Portugal on November 2-4, 2017, is Design the Future, starting from the crossroads of ideas and debates, a new starting point for the exploration of textile materials, their identities and innovations in all their dimensions.
Download or read book Shape Memory Alloys for Small Scale Actuation written by Ashley Jessica Hartwell and published by . This book was released on 2018 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt: Shape Memory Alloys (SMAs), materials that can undergo a fully recoverable strain change due to a thermal cycle, and which can be produced in a form that is superelastic are only utilized limitedly. In this thesis, I investigated the relationship between the material properties of shape memory alloy micro-wires and their mechanical performance. This study was conducted with two main types of SMAs, the first a commercially available NiTi wire, and the second an emerging Cu-based alternative. This comparison allows an understanding of the current state of the art for small scale actuation with SMA wires, and to evaluate the Cu-based alternative SMA, which has a reduced cost and improved thermal properties. This thesis evaluates Cu-based SMAs as substitutes for NiTi in terms of activation strain of wire during a shape memory cycle, power consumption during actuation, heating and cooling times during actuation, and cost. Furthermore this thesis includes studies on the processing of Cu-based alternatives to enhance shape memory properties of interests, such as transformation temperature and fatigue, and suggests future work to improve Cu-based SMA wires..
Download or read book Improving Residual Stress and Heat Transfer in Shape Memory Alloy Actuation written by Lawrence Bradley and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Shape memory alloys (SMA) are a class of functional materials that are best known for their very high strength to weight ratio as actuators. This is due to temperature dependent phase transformation, which allows 4-6% strain. When heated, they contract in length -- thereby producing very large actuation force. Despite their unique properties, the applications of shape memory alloys as actuators are limited by (a) slow actuation rate that is critically influenced by cooling time and (b) residual stress in the material that reduce the amount of the recoverable strain. In the first part of this research, we propose a new actuation mode where we integrate conduction mode heat transfer in the SMA wire, without any additional element that increases size of weight of the actuators. This is motivated by the observation that the it is not possible to improve natural convective heat transfer for a given specimen cross-section and that conduction mode is faster than convection. We propose a 'segmented actuation' where instead of heating the entire length of the wire, we piecewise segment it and perform controlled heating. This allows the unheated segment (neighboring two heated ones) act as a temporary heatsink that receives heat by conduction. Using a controller along with segmented heating of the alloy, we demonstrate that the actuation rate can be improved three-fold, without any change in the shape memory properties. However, the segmented approach essentially costs some recoverable strain. In the second part of this research, we focus on the residual stress in the SMA wire, which is difficult to avoid because the wires are manufacturing by drawing process. We propose a unique annealing process that works at significantly lower temperature (
Download or read book Characterization and Application of Shape Memory Alloy Wires for Micro and Meso Positioning Systems written by and published by . This book was released on 2002 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Characterization and application of Shape Memory Alloy wires for micro and meso positioning systems.
Download or read book SMArt Muscle written by Kasper Roed Jensen and published by . This book was released on 2005 with total page 137 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Shape Memory Alloy Micro actuators for Bio medical Applications written by Sheng Long Mao and published by . This book was released on 2003 with total page 132 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Actuation Training and Its Effects on Actuation Fatigue of Nitinol Shape Memory Wires written by Pete A. Rocco and published by . This book was released on 2019 with total page 53 pages. Available in PDF, EPUB and Kindle. Book excerpt: Shape memory alloys (SMAs) possess unique properties which make them a great candidate in many applications. Nitinol is the most famous SMA that have been used widely in aerospace, biomedical, civil, and automotive industries. Shape Memory Effect (SME) is the feature that allows Nitinol to recover large amount of deformation by heating it up above its transformation temperature. In addition to SME, high actuation energy density of the SMAs qualified them to be used as a compact and lightweight actuator in many applications. Generally, actuators undergo repetitive loading-unloading conditions. In case of wire actuators, Nitinol wires can be deformed by the actual loads and then will recover to their original shape by heating them up and this process is repeatable. Heating and cooling the actuators for specific number of cycles under specific level of load prior to the actual application is called training. Training has been used to stabilize the strain recovery of SME NiTi actuators. However, training could also affect the actuation fatigue life and need to be more investigated. In this study in order to evaluate the actuation fatigue life as well as the effect of the training on the fatigue life of the Nitinol wire actuators a setup was built. In this setup, the Nitinol wires were loaded at a constant load, and then were heated up via Joule heating to lift the weights. Then the wires were cooled down to become deactivated and then the cycles continued. The number of cycles to failure, as well the mechanical response, for different types of loading were recorded. The fracture surface of the samples was analyzed using SEM. The results showed that the actuation fatigue life of Nitinol wires decreased linearly in logarithmic scale by increasing the actuation load. Experimenting the trained Nitinol wires showed that the training has the capacity to increase the actuation fatigue life of the Nitinol wires by a factor of 2. However, the effect of training strongly depends on the level of load used for the training procedure and the actuation load in the main application. Evaluating the fracture surfaces revealed that the fracture mechanism in trained samples is different from the ones in not-trained samples. Trained samples showed a more ductile fracture mechanism, while the virgin samples showed a relatively brittle fracture type.
Download or read book An Application of Shape Memory Metal Alloys written by Dennis Son and published by . This book was released on 1996 with total page 108 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Investigation of Shape Memory Alloy Wire for Closed Loop Angular Position Control of a Shaft Under Random Excitation written by Brian Kennedy Lynch and published by . This book was released on 2007 with total page 172 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Design and Control of a Shape Memory Alloy Linear Actuator written by Patti Sue Brown and published by . This book was released on 1988 with total page 362 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Shape Memory Polymers written by Jinlian Hu and published by Smithers Rapra. This book was released on 2014-05-27 with total page 326 pages. Available in PDF, EPUB and Kindle. Book excerpt: Shape-memory polymers (SMP) are a unique branch of the smart materials family which are capable of changing shape on-demand upon exposure to external stimulus. The discovery of SMP made a significant breakthrough in the developments of novel smart materials for a variety of engineering applications, superseded the traditional materials, and also influenced the current methods of product designing. This book provides the latest advanced information of on-going research domains of SMP. This will certainly enlighten the reader to the achievements and tremendous potentials of SMP. The basic fundamentals of SMP, including shape-memory mechanisms and mechanics are described. This will aid reader to become more familiar with SMP and the basic concepts, thus guiding them in undergoing independent research in the SMP field. The book also provides the reader with associated challenges and existing application problems of SMP. This could assist the reader to focus more on these issues and further exploit their knowledge to look for innovative solutions. Future outlooks of SMP research are discussed as well. This book should prove to be extremely useful for academics, R&D managers, researcher scientists, engineers, and all others related to the SMP research.
