Download or read book Process Development and Characterization to Manufacture Nickel Titanium Shape Memory Cantilever Micro electro mechanical Systems written by Dustin Michael Dequine and published by . This book was released on 2007 with total page 242 pages. Available in PDF, EPUB and Kindle. Book excerpt: A study to document the fabrication process and to make a start on characterizing the steps required to create a shape memory nickel titanium cantilever structure. Applications for micro systems cantilever devices include micro valves, switches, actuators, pumps, and grippers.

Download or read book Thermomechanical Characterization of Nickel Titanium Copper Shape Memory Alloy Films written by KP. Seward and published by . This book was released on 2001 with total page 13 pages. Available in PDF, EPUB and Kindle. Book excerpt: In an effort to develop a more extensive model for the thermomechanical behavior of shape memory alloy (SMA) films, a novel characterization method has been developed. This automated test has been tailored to characterize films for use in micro-electromechanical system (MEMS) actuators. The shape memory effect in NiTiCu is seen in the solid-state phase transformation from an easily deformable low-temperature state to a "shape remembering" high-temperature state. The accurate determination of engineering properties for these films necessitates measurements of both stress and strain in microfabricated test structures over the full range of desired deformation. Our various experimental methods (uniaxial tensile tests, bimorph curvature tests, and diaphragm bulge tests) provide recoverable stress and strain data and the stress-strain relations for these films. Tests were performed over a range of temperatures by resistive heating or ambient heating. These measurements provide the results necessary for developing active SMA structural film design models.

Download or read book Sputter Deposition and Characterization of Thin Film Nickel Titanium Shape Memory Alloy for Microelectromechanical Systems Application written by Ken Khinh Ho and published by . This book was released on 2001 with total page 260 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Characterization of Thin Film Nickel Titanium Shape Memory Alloys written by Nicole Latrice Harris Odum and published by . This book was released on 2010 with total page 126 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Mems for Biomedical Applications written by Shekhar Bhansali and published by Elsevier. This book was released on 2012-07-18 with total page 511 pages. Available in PDF, EPUB and Kindle. Book excerpt: The application of Micro Electro Mechanical Systems (MEMS) in the biomedical field is leading to a new generation of medical devices. MEMS for biomedical applications reviews the wealth of recent research on fabrication technologies and applications of this exciting technology.The book is divided into four parts: Part one introduces the fundamentals of MEMS for biomedical applications, exploring the microfabrication of polymers and reviewing sensor and actuator mechanisms. Part two describes applications of MEMS for biomedical sensing and diagnostic applications. MEMS for in vivo sensing and electrical impedance spectroscopy are investigated, along with ultrasonic transducers, and lab-on-chip devices. MEMS for tissue engineering and clinical applications are the focus of part three, which considers cell culture and tissue scaffolding devices, BioMEMS for drug delivery and minimally invasive medical procedures. Finally, part four reviews emerging biomedical applications of MEMS, from implantable neuroprobes and ocular implants to cellular microinjection and hybrid MEMS.With its distinguished editors and international team of expert contributors, MEMS for biomedical applications provides an authoritative review for scientists and manufacturers involved in the design and development of medical devices as well as clinicians using this important technology. - Reviews the wealth of recent research on fabrication technologies and applications of Micro Electro Mechanical Systems (MEMS) in the biomedical field - Introduces the fundamentals of MEMS for biomedical applications, exploring the microfabrication of polymers and reviewing sensor and actuator mechanisms - Considers MEMS for biomedical sensing and diagnostic applications, along with MEMS for in vivo sensing and electrical impedance spectroscopy

Download or read book Laser Processing Thermomechanical Processing and Thermomechanical Fatigue of NiTi Shape Memory Alloys written by Boyd Panton and published by . This book was released on 2016 with total page 143 pages. Available in PDF, EPUB and Kindle. Book excerpt: NiTi shape memory alloys (SMAs) have revolutionized engineering design across all industries, with major contributions in the medical, aerospace, and automotive industries. These fascinating materials possess the shape memory effect, pseudoelastic effect and biocompatibility, which make them so highly desired. Since their discovery mid-way through the 20th century a large research effort has been underway to gain fundamental understanding of the mechanisms responsible for their properties. The material properties depend on a large number of variables including the microstructure, the texture, the stress/strain state, and the temperature. An understanding of the interdependence of these variables is still being developed, with particular focus on their evolution when either multi-axial loading, or fatigue cycling are applied to the material. Furthermore, the advanced manufacturing techniques required to properly process NiTi have only recently become a reality, with further advancements being developed to continue pushing the limits of these materials. One limitation of NiTi is that standard manufactured products have only one transformation temperature. A number of techniques have been developed in an attempt to address this limitation and increase the functionality of SMAs. A highly accurate and repeatable technique was recently developed that uses a high energy density process (e.g. laser) to alter the composition of NiTi in localized regions. Laser processing enables the tailoring of different regions of a single piece of NiTi to have different transformation properties. However, there have been no in-depth studies of the evolution of the properties of these laser processed materials over multiple mechanical or thermal cycles. This lack of fundamental knowledge significantly limits both the understanding and possibilities for the application of laser processed NiTi. In addition to this limitation, the most widely used form of NiTi SMA is wires, but the major studies on laser processing have focused on sheets. Investigation of the evolution of laser processed NiTi wires over multiple mechanical or thermal cycles would not only benefit laser processing technologies, but it would also improve the general understanding of SMAs, with benefits to other areas including other local processing techniques, welding and joining, mechanical and thermomechanical fatigue. The current study investigated the evolution of the properties of laser processed NiTi when the materials were subjected to thermal cycling, mechanical cycling, and fatigue cycling. The knowledge gained was used to identify limitations in the current technology, and develop thermomechanical treatments to address these limitations. The first part of the investigation focused on a wire that had a single laser processed spot (i.e. a laser weld). Few investigations have been attempted to characterize the mechanical fatigue properties of NiTi joints, and to the author's knowledge there have been no previous investigations on the thermomechanical fatigue properties of these joints. The current work investigated the thermomechanical fatigue properties of Nd:YAG pulsed laser welded, and post-weld heat treated NiTi wires. The welded wires maintained over 86 % of the base metal ultimate tensile strength; however, they had reduced actuation stability and stroke, and had significantly reduced cycle life. Use of a post-weld heat treatment successfully increased both the actuation stability and the cycle life by an order of magnitude compared to the welded wires. The second part of the investigation focused on the development and characterization of laser processing techniques for NiTi wires. The process altered the composition of the NiTi wire with a reduction of 0.23 at.% Ni for each laser pulse after the first pulse. The first laser pulse removed 0.40 at.% Ni, which was a larger amount than the following pulses, because the wire drawn surface finish was less reflective than the laser processed surface. The coarse grained laser processed NiTi had 71 % of the base metal ultimate tensile strength, 40 % of the base metal ductility, significant reduction in the stability of the shape memory properties, and an almost complete loss of the fatigue life of the base metal. Using the fundamental knowledge gained from this investigation a thermomechanical treatment was developed to improve the properties of the laser processed NiTi. The treated laser processed NiTi had an ultimate tensile strength matching the base metal and a ductility 70 % greater than the laser processed NiTi. Significant improvement to the shape memory properties were achieved, with a return of pseudoelasticity, and an 80% greater shape memory recovery than the untreated laser processed NiTi. Furthermore the low strain (i.e. 2%) thermomechanical fatigue lives of the treated laser processed NiTi were equal to the base metal. Finally, actuators were developed with two distinct memories, with the treated actuator having 33 % lower plastic strain, and 42 % greater shape memory recovery than the untreated actuator. This technology was exploited to develop a self-biasing actuator. A shape memory alloy (SMA) actuator that is biased internally (i.e. self-biasing) would not need an external bias to achieve multiple actuation cycles. This would reduce cost, complexity and weight compared to standard one-way SMAs. The self-biasing actuators that have been developed to date have a lack of geometric and actuation stability. The current study developed a self-biasing NiTi actuator using a laser based vaporization process to alter the bulk composition of a NiTi wire. The martensitic laser processed NiTi region was the actuator, and un-processed austenitic base metal region was the internal bias. It was discovered that the laser processed region of the self-biasing actuator was unstable during high stress thermomechanical cycling due to the coarse grained microstructure. Cold-working of the half martensitic and half austenitic component resulted in similar deformation characteristics to single phase NiTi, which enabled the formation of a uniform nanocrystalline microstructure in both regions. When thermomechanically cycled 6000 times under stresses ranging from 180 to 400 MPa, it was discovered that this treated self-biasing actuator exhibited the stabilization behaviour of traditional one-way actuators. This behaviour was due to the uniform nanocrystalline microstructure, which impeded dislocation activity and ensured minimal plastic deformation.

Download or read book Sputter Deposition of Thin Film Nickel Titanium Shape Memory Alloy for Microelectromechanical Systems Application written by Ken Khinh Ho and published by . This book was released on 1997 with total page 158 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Development and Processing of Nickel Titanium Shape Memory Alloys Containing Palladium Using Selective Laser Melting written by Hollie L. Baker and published by . This book was released on 2019 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nitinol (NiTi) is a commonly used biomaterial, due to its unique superelasticity and shape memory effect. However, NiTi has a low radiopacity, so it is difficult to observe using electromagnetic radiation once inside the body. The radiopacity of NiTi can be improved by alloying with a denser, ternary element. Platinum (Pt) is a popular choice as a result of its biocompatibility and corrosion resistance. However, alloying with palladium (Pd) is fast becoming a viable alternative due to its similar properties and much lower cost. The overall purpose of this thesis is to investigate the suitability of selective laser melting (SLM) for manufacturing palladium (Pd) modified nickel-titanium (NiTi) shape memory alloys (SMAs), that can be used in biomedical devices within the human body. This study presents a methodology for in-situ alloying Pd into NiTi using selective laser melting (SLM) to manufacture dense, defect free components. The influence of melt pool dimensions on chemical homogeneity was investigated. The laser power, laser scanning velocity and laser scan spacing were independently varied to alter the energy density of the laser and in turn, modify the dimensions of the melt pool. It has been found that the SLM process parameters can be manipulated to fully diffuse Pd into the NiTi matrix, providing a homogenous microstructure. Out of the three process parameters investigated, the scan velocity had the greatest influence on the melt pool. Thus, increasing the dissolution of Pd as a result of the Marangoni effect and increased melt pool liquid life span. The suitability of the dense and chemically homogeneous SLM fabricated TiNiPd alloys were investigated for their use in biomedical applications. Furthermore, the effects of Pd on the properties of the binary NiTi alloy were also studied. This was performed by testing the alloy's phase transformation behaviour, cell biocompatibility, corrosion resistance, superelastic response and X-ray visibility. Overall, it can be concluded that the addition of Pd had advantageous benefits towards improving the properties of binary NiTi for use in biomedical applications. Alloying with 7 at % Pd in substitution for Ni, was found to improve the alloy's corrosion resistance, X-ray visibility and biocompatibility, thus making the ternary TiNiPd alloy a promising biomaterial.

Download or read book Development and Characterization of Self assembly Using Residual Stress in a Multi user Polymer MEMS Process written by Sae-Won Lee and published by . This book was released on 2008 with total page 128 pages. Available in PDF, EPUB and Kindle. Book excerpt: A novel self-assembly method is presented for creating self-assembled three-dimensional micro-electro-mechanical systems (MEMS) structures. The residual stress between structural polymer layers caused by separate curing processes has been used as the self-assembly mechanism. Various radii of curvature are presented using this self-assembly method in order to show the capability of fabricating three-dimensional microstructures. SU-8 negative photoresist is used as a structural material, and induced stresses are lithographically defined for self-assembly. The self-assembly mechanism is simulated using finite element analysis in ANSYS. Several types of self-assembled microstructures are presented. The fabrication is performed at low temperatures and is compatible with commercial integrated-circuit processes.

Download or read book International Aerospace Abstracts written by and published by . This book was released on 1998 with total page 980 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book MEMS Materials and Processes Handbook written by Reza Ghodssi and published by Springer Science & Business Media. This book was released on 2011-03-18 with total page 1211 pages. Available in PDF, EPUB and Kindle. Book excerpt: MEMs Materials and Processes Handbook" is a comprehensive reference for researchers searching for new materials, properties of known materials, or specific processes available for MEMS fabrication. The content is separated into distinct sections on "Materials" and "Processes". The extensive Material Selection Guide" and a "Material Database" guides the reader through the selection of appropriate materials for the required task at hand. The "Processes" section of the book is organized as a catalog of various microfabrication processes, each with a brief introduction to the technology, as well as examples of common uses in MEMs.

Download or read book Electrical Electronics Abstracts written by and published by . This book was released on 1997 with total page 1948 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Advanced Functional Materials written by Nevin Tasaltin and published by . This book was released on 2020 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Engineering Aspects of Shape Memory Alloys written by T W Duerig and published by Butterworth-Heinemann. This book was released on 2013-10-22 with total page 512 pages. Available in PDF, EPUB and Kindle. Book excerpt: Engineering Aspects of Shape Memory Alloys provides an understanding of shape memory by defining terms, properties, and applications. It includes tutorials, overviews, and specific design examples—all written with the intention of minimizing the science and maximizing the engineering aspects. Although the individual chapters have been written by many different authors, each one of the best in their fields, the overall tone and intent of the book is not that of a proceedings, but that of a textbook. The book consists of five parts. Part I deals with the mechanism of shape memory and the alloys that exhibit the effect. It also defines many essential terms that will be used in later parts. Part II deals primarily with constrained recovery, but to some extent with free recovery. There is an introductory paper which defines terms and principles, then several specific examples of products based on constrained recovery. Both Parts III and IV deal with actuators. Part III introduces engineering principles while Part IV presents several of the specific examples. Finally, Part V deals with superelasticity, with an introductory paper and then several specific examples of product engineering.

Download or read book Additive Manufacturing Hybrid Processes for Composites Systems written by António Torres Marques and published by Springer Nature. This book was released on 2020-04-27 with total page 346 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book focuses on the emerging additive manufacturing technology and its applications beyond state-of-the-art, fibre-reinforced thermoplastics. It also discusses the development of a hybrid, integrated process that combines additive and subtractive operations in a single-step platform, allowing CAD-to-Part production with freeform shapes using long or continuous fibre-reinforced thermoplastics. The book covers the entire value chain of this next-generation technology, from part design and materials composition to transformation stages, product evaluation, and end-of-life studies. Moreover, it addresses the following engineering issues: • Design rules for hybrid additive manufacturing; • Thermoplastic compounds for high-temperature and -strength applications; • Advanced extrusion heads and process concepts; • Hybridisation strategies; • Software ecosystems for hAM design, pre-processing, process planning, emulating and multi-axis processing; • 3D path generators for hAM based on a multi-objective optimisation algorithm that matches the recent curved adaptive slicing method with a new transversal scheme; • hAM parameters, real-time monitoring and closed-loop control; • Multiparametric nondestructive testing (NDT) tools customised for FRTP AM parts; • Sustainable manufacturing processes validated by advanced LCA/LCC models.

Download or read book Microfluidic Devices for Biomedical Applications written by Xiujun James Li and published by Woodhead Publishing. This book was released on 2013-10-31 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Microfluidics or lab-on-a-chip (LOC) is an important technology suitable for numerous applications from drug delivery to tissue engineering. Microfluidic devices for biomedical applications discusses the fundamentals of microfluidics and explores in detail a wide range of medical applications. The first part of the book reviews the fundamentals of microfluidic technologies for biomedical applications with chapters focussing on the materials and methods for microfabrication, microfluidic actuation mechanisms and digital microfluidic technologies. Chapters in part two examine applications in drug discovery and controlled-delivery including micro needles. Part three considers applications of microfluidic devices in cellular analysis and manipulation, tissue engineering and their role in developing tissue scaffolds and stem cell engineering. The final part of the book covers the applications of microfluidic devices in diagnostic sensing, including genetic analysis, low-cost bioassays, viral detection, and radio chemical synthesis. Microfluidic devices for biomedical applications is an essential reference for medical device manufacturers, scientists and researchers concerned with microfluidics in the field of biomedical applications and life-science industries.

Download or read book Shape Memory and Superelastic Alloys written by K Yamauchi and published by Elsevier. This book was released on 2011-04-30 with total page 225 pages. Available in PDF, EPUB and Kindle. Book excerpt: Shape memory and superelastic alloys possess properties not present in ordinary metals meaning that they can be used for a variety of applications. Shape memory and superelastic alloys: Applications and technologies explores these applications discussing their key features and commercial performance. Readers will gain invaluable information and insight into the current and potential future applications of shape memory alloys.Part one covers the properties and processing of shape memory effect and superelasticity in alloys for practical users with chapters covering the basic characteristics of Ti-Ni-based and Ti-Nb-based shape memory and superelastic (SM/SE) alloys, the development and commercialisation of TiNi and Cu-based alloys, industrial processing and device elements, design of SMA coil springs for actuators before a final overview on the development of SM and SE applications. Part two introduces SMA application technologies with chapters investigating SMAs in electrical applications, hot-water supply, construction and housing, automobiles and railways and aerospace engineering before looking at the properties, processing and applications of Ferrous (Fe)-based SMAs. Part three focuses on the applications of superelastic alloys and explores their functions in the medical, telecommunications, clothing, sports and leisure industries. The appendix briefly describes the history and activity of the Association of Shape Memory Alloys (ASMA).With its distinguished editors and team of expert contributors, Shape memory and superelastic alloys: Applications and technologies is be a valuable reference tool for metallurgists as well as for designers, engineers and students involved in one of the many industries in which shape memory effect and superelasticity are used such as construction, automotive, medical, aerospace, telecommunications, water/heating, clothing, sports and leisure. - Explores important applications of shape memory and superelastic alloys discussing their key features and commercial performance - Assesses the properties and processing of shape memory effect and superelasticity in alloys for practical users with chapters covering the basic characteristics - Introduces SMA application technologies investigating SMAs in electrical applications, hot-water supply, construction and housing, automobiles and railways and aerospace engineering