Download or read book Thin Film NiTi Shape Memory Alloy Microactuators written by John J. Gill and published by . This book was released on 2001 with total page 218 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Thin Film Shape Memory Alloys written by Shuichi Miyazaki and published by Cambridge University Press. This book was released on 2009-09-03 with total page 487 pages. Available in PDF, EPUB and Kindle. Book excerpt: The first dedicated book describing the properties, preparation, characterization and device applications of TiNi-based shape memory alloys.

Download or read book Shape Memory Microactuators written by Manfred Kohl and published by Springer Science & Business Media. This book was released on 2013-03-09 with total page 265 pages. Available in PDF, EPUB and Kindle. Book excerpt: Overview of recent achievements, describing the microactuator development of microvalves and liner actuators comprehensively from concept through prototype. Further key aspects included are three-dimensional models for handling complex SMA actuator geometries and coupled simulation routines that take multifunctional properties into account. Mechanical and thermal optimization criteria are introduced for actuator design, allowing an optimum use of the shape memory effect. It is shown that some of the prototypes presented, e.g. SMA microgrippers, already outperform conventional components.

Download or read book Shape Memory Alloy Actuators written by Mohammad H. Elahinia and published by John Wiley & Sons. This book was released on 2016-01-19 with total page 297 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a systematic approach to realizing NiTi shape memory alloy actuation, and is aimed at science and engineering students who would like to develop a better understanding of the behaviors of SMAs, and learn to design, simulate, control, and fabricate these actuators in a systematic approach. Several innovative biomedical applications of SMAs are discussed. These include orthopedic, rehabilitation, assistive, cardiovascular, and surgery devices and tools. To this end unique actuation mechanisms are discussed. These include antagonistic bi-stable shape memory-superelastic actuation, shape memory spring actuation, and multi axial tension-torsion actuation. These actuation mechanisms open new possibilities for creating adaptive structures and biomedical devices by using SMAs.

Download or read book TiNi Shape Memory Alloy Thin Film Rotating Micro actuators written by Cho Chiu Ma and published by . This book was released on 1999 with total page 138 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A New Mechanical Characterization Method for Thin Film Microactuators and Its Application to NiTiCi Shape Memory Alloy written by and published by . This book was released on 1999 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In an effort to develop a more full characterization tool of shape memory alloys, a new technique is presented for the mechanical characterization of microactuators and applied to SMA thin films. A test instrument was designed to utilize a spring-loaded transducer in measuring displacements with resolution of 1.5 pm and forces with resolution of 0.2 mN. Employing an out-of-plane loading method for freestanding SMA thin films, strain resolution of 30[mu][epsilon] and stress resolution of 2.5 MPa were achieved. This new testing method is presented against previous SMA characterization methods for purposes of comparison. Four mm long, 2 [mu]m thick NiTiCu ligaments suspended across open windows were bulk micromachined for use in the out-of-plane stress and strain measurements. The fabrication process used to micromachine the ligaments is presented step-by-step, alongside methods of fabrication that failed to produce testable ligaments. Static analysis showed that 63% of the applied strain was recovered while ligaments were subjected to tensile stresses of 870 MPa. In terms of recoverable stress and recoverable strain, the ligaments achieved maximum recovery of 700 MPa and 3.0% strain. No permanent deformations were seen in any ligament during deflection measurements. Maximum actuation forces and displacements produced by the 4 mm ligaments situated on 1 cm square test chips were 56 mN and 300 [mu]m, respectively. Fatigue analysis of the ligaments showed degradation in recoverable strain from 0.33% to 0.24% with 200,000 cycles, corresponding to deflections of 90 [mu]m and forces of 25 mN. Cycling also produced a wavering shape memory effect late in ligament life, leading to broad inconsistencies of as much as 35% deviation from average. Unexpected phenomena like stress-induced martensitic twinning that leads to less recoverable stress and the shape memory behavior of long life devices are addressed. Finally, a model for design of microactuators using shape memory alloys is presented to illustrate how results obtained from these tests can be interpreted and applied to the creation of MEMS devices.

Download or read book A New Mechanical Characterization Method for Thin Film Microactuators and Its Application to NiTiCu Shape Memory Alloy written by Kirk Patrick Seward and published by . This book was released on 1999 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Fabrications of Shape Memory Alloy Thin Films and NiTi Microvalves Based on Micro Electro Mechanical System MEMS Techniques written by 尤良 and published by . This book was released on 2004 with total page 276 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book NiTi Shape Memory Alloy Thin Film Based Microgripper written by Jun Ping Tan and published by . This book was released on 2001 with total page 146 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Development of Nano Structured Thin Film Shape Memory Alloys for MEMS Applications written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The production of thin film TiPdNi shape memory alloys (SMA) using ion beam assisted deposition (IBAD) is being studied as a way to increase the actuation frequencies and transformation temperatures of thin film SMA for micro-actuator applications. The capability to transmit extremely high forces along with a large stroke, large strain memory, and high corrosion resistance makes shape memory alloys prime candidates for use in micro-actuator applications. However, low actuation frequency (~1Hz at macro-scale), and low transition temperature (below 100°C) makes commercially available NiTi incompatible with applications in extreme environments. The transformation temperature and actuation frequency of shape memory alloys can be improved through the production of thin film TiPdNi. Through the substitution of Pd for Ni in equiatomic NiTi, the transformation temperature can be varied from approximately room temperature to 527°C. The composition that has received the most attention is Ti50Pd30Ni20 because of its transformation temperature of over 200°C. However, the shape memory effect of Ti50Pd30Ni20 is adversely affected by the low critical stress needed for slip at high temperatures, which results in unrecoverable strain. Age hardening or thermo-mechanical treatments such as cold rolling have been found to improve the critical stress for slip in bulk form SMA due to an increased density of dislocations. Precipitation hardening, as well as, ion bombardment, is expected to increase the high temperature properties in IBAD deposited Ti50Pd30Ni20 film SMA. Additionally, ion bombardment during deposition can be used to improve film properties such as morphology, density, stress level, crystallinity, as well as, limit defects. Due to the refined grain size, increased density, and reduced defects, IBAD is able to produce films of 1 micron or less, which will greatly reduces the SMA actuation time due to the increased surface area --to -- volume ratio. In t.

Download or read book Optimization of MEMS Actuator Driven by Shape Memory Alloy Thin Film Phase Change written by Cory R. Knick and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: At the microscale, shape memory alloy (SMA) microelectromechanical system (MEMS) bimorph actuators offer great potential based on their inherently high work density. An optimization problem relating to the deflection and curvature based on shape memory MEMS bimorph was identified, formulated, and solved. Thicknesses of the SU-8 photoresist and nickel-titanium alloy (NiTi) was identified that yielded maximum deflections and curvature radius based on a relationship among individual layer thicknesses, elastic modulus, and cantilever length. This model should serve as a guideline for optimal NiTi and SU-8 thicknesses to drive large deflections and curvature radius that are most suitable for microrobotic actuation, micromirrors, micropumps, and microgrippers. This model would also be extensible to other phase-change-driven actuators where nonlinear and significant residual stress changes are used to drive actuation.

Download or read book Shape Memory Alloys for Biomedical Applications written by T Yoneyama and published by Elsevier. This book was released on 2008-11-21 with total page 354 pages. Available in PDF, EPUB and Kindle. Book excerpt: Shape memory alloys are suitable for a wide range of biomedical applications, such as dentistry, bone repair and cardiovascular stents. Shape memory alloys for biomedical applications provides a comprehensive review of the use of shape memory alloys in these and other areas of medicine. Part one discusses fundamental issues with chapters on such topics as mechanical properties, fabrication of materials, the shape memory effect, superelasticity, surface modification and biocompatibility. Part two covers applications of shape memory alloys in areas such as stents and orthodontic devices as well as other applications in the medical and dental fields. With its distinguished editors and international team of contributors, Shape memory alloys for biomedical applications is an essential reference for materials scientists and engineers working in the medical devices industry and in academia. A comprehensive review of shape memory metals and devices for medical applications Discusses materials, mechanical properties, surface modification and biocompatibility Chapters review medical and dental devices using shape memory metals, including stents and orthodontic devices

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 Development of Microactuators Based on the Magnetic Shape Memory Effect written by Yeduru, Srinivasa Reddy and published by KIT Scientific Publishing. This book was released on 2013-12-10 with total page 184 pages. Available in PDF, EPUB and Kindle. Book excerpt: The giant magneto-strain effect in Ni-Mn-Ga alloys is particularly attractive for actuator applications. Two different approaches are being pursued to develop MSM microactuators. To observe large deflections of Ni-Mn-Ga microactuators, the material should be exhibiting low twinning stress and large magnetic anisotropy. In addition, design rules and boundary conditions for operating the Ni-Mn-Ga actuator material are having significant importance for evolution of performance characteristics.

Download or read book A New Mechanical Characterization Method for Microactuators Applied to Shape Memory Films written by and published by . This book was released on 1999 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We present a new technique for the mechanical characterization of microactuators and apply it to shape memory alloy (SMA) thin films. A test instrument was designed which utilizes a spring-loaded transducer to measure displacements with resolution of 1.5 mm and forces with resolution of 0.2 mN. Employing an out- of-plane loading method for SMA thin films, strain resolution of 30 me and stress resolution of 2.5 MPa were achieved. Four mm long, 2 [mu]m thick NiTiCu ligaments suspended across open windows were bulk micromachined for use in the out-of-plane stress and strain measurements. Static analysis showed that 63% of the applied strain was recovered while ligaments were subjected to tensile stresses of 870 MPa. This corresponds to 280 mm of actual displacement against a load of 52 mN. Fatigue analysis of the ligaments showed 33% degradation in recoverable strain (from 0.3% to 0.2%) with 2 ± 104 cycles for an initial strain of 2.8%.

Download or read book Shape Memory Alloys Handbook written by Christian Lexcellent and published by John Wiley & Sons. This book was released on 2013-04-08 with total page 295 pages. Available in PDF, EPUB and Kindle. Book excerpt: The aim of this book is to understand and describe the martensitic phase transformation and the process of martensite platelet reorientation. These two key elements enable the author to introduce the main features associated with the behavior of shape-memory alloys (SMAs), i.e. the one-way shape-memory effect, pseudo-elasticity, training and recovery. Attention is paid in particular to the thermodynamical frame for solid materials modeling at the macroscopic scale and its applications, as well as to the particular use of such alloys – the simplified calculations for the bending of bars and their torsion. Other chapters are devoted to key topics such as the use of the “crystallographical theory of martensite” for SMA modeling, phenomenological and statistical investigations of SMAs, magneto-thermo-mechanical behavior of magnetic SMAs and the fracture mechanics of SMAs. Case studies are provided on the dimensioning of SMA elements offering the reader an additional useful framework on the subject. Contents 1. Some General Points about SMAs. 2. The World of Shape-memory Alloys. 3. Martensitic Transformation. 4. Thermodynamic Framework for the Modeling of Solid Materials. 5. Use of the “CTM” to Model SMAs. 6. Phenomenological and Statistical Approaches for SMAs. 7. Macroscopic Models with Internal Variables. 8. Design of SMA Elements: Case Studies. 9. Behavior of Magnetic SMAs. 10. Fracture Mechanics of SMAs. 11. General Conclusion. Appendix 1. Intrinsic Properties of Rotation Matrices. Appendix 2. “Twinning Equation” Demonstration. Appendix 3. Calculation of the Parameters a, n and Q from the “Twinning” Equation. Appendix 4. “Twinned” Austenite/Martensite Equation. About the Authors Christian Lexcellent is Emeritus Professor at the École National Supérieure de Mécanique et des Microtechniques de Besançon and a researcher in the Department of Applied Mechanics at FEMTO-ST in France. He is a specialist in the mechanics of materials and phase transition and has taught in the subjects of mechanics of continuum media and shape memory alloys. He is also a member of the International Committee of ESOMAT.

Download or read book Fabrication and Characterization of Nanoscale Shape Memory Alloy MEMS Actuators written by Cory R. Knick and published by . This book was released on 2019 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The miniaturization of engineering devices has created interest in new actuation methods capable of large displacements and high frequency responses. Shape memory alloy (SMA) thin films have exhibited one of the highest power densities of any material used in these actuation schemes and can thermally recovery strains of up to 10%. Homogenous SMA films can experience reversible shape memory effect, but without some sort of physical biasing mechanism, the effect is only one-way. SMA films mated in a multi-layer stack have the appealing feature of an intrinsic two-way shape memory effect (SME). In this work, we developed a near-equiatomic NiTi magnetron co-sputtering process and characterized shape memory effects. We mated these SMA films in several ,Äúbimorph,Äù configurations to induce out of plane curvature in the low-temperature Martensite phase. We quantify the curvature radius vs. temperature on MEMS device structures to elucidate a relationship between residual stress, recovery stress, radius of curvature, and degree of unfolding. We fabricated and tested laser-irradiated and joule heated SMA MEMS actuators to enable rapid actuation of NiTi MEMS devices, demonstrating some of the lowest powers (5,Äì15 mW) and operating frequencies (1,Äì3 kHz) ever reported for SMA or other thermal actuators.