A shape memory microcage of TiNi/DLC films for biological applications

Fu, Yong Qing; Luo, Jikui; Ong, Soon-Eng; Zhang, Sam; Flewitt, Andrew J.; Milne, W. I.

doi:10.1088/0960-1317/18/3/035026

Cited by 34 publications

(27 citation statements)

References 21 publications

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“…The annealing process is performed at high temperature (normally over 450°C) to form a crystalline structure of NiTi, e.g., martensite, austenite, and R-phase. The annealing is typically performed by heating an as-deposited Ni-Ti thin film in a high vacuum furnace ( Ref 11,15,16). However, there are several other possibilities for annealing such as heating by high-power laser (Ref 17), heating by halogen lamp (Ref 18), and heating in a quartz tube furnace with inert gas overflow ( Ref 12).…”

Section: Introductionmentioning

confidence: 99%

Fabrication and Characterization of Nitinol-Copper Shape Memory Alloy Bimorph Actuators

Wongweerayoot

Srituravanich

Pimpin

2014

J. of Materi Eng and Perform

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This study aims to examine the effect of annealing conditions on nitinol (NiTi) characteristics and applies this knowledge to fabricate a NiTi-copper shape memory alloy bimorph actuator. The effect of the annealing conditions was investigated at various temperatures, i.e., 500, 600, and 650°C, for 30 min. With the characterizations using x-ray diffraction, energy dispersive spectroscopy, and differential scanning calorimetry techniques, the results showed that annealing temperatures at 600 and 650°C were able to appropriately form the crystalline structure of NiTi. However, at these high annealing temperatures, the oxide on a surface was unavoidable. In the fabrication of actuator, the annealing at 650°C for 30 min was chosen, and it was performed at two pre-stressing conditions, i.e., straight and curved molds. From static and dynamic response experiments, the results suggested that the annealing temperature significantly affected the deflection of the actuator. On the other hand, the effect of pre-stressing conditions was relatively small. Furthermore, the micro gripper consisting of two NiTi-copper bimorph actuators successfully demonstrated for the viability of small object manipulation as the gripper was able to grasp and hold a small plastic ball with its weight of around 0.5 mg.

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Section: Introductionmentioning

confidence: 99%

Fabrication and Characterization of Nitinol-Copper Shape Memory Alloy Bimorph Actuators

Wongweerayoot

Srituravanich

Pimpin

2014

J. of Materi Eng and Perform

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“…Based on the large displacements and actuation forces possible a number of thin film SMA applications have been developed, i.e. micropumps [2e5], -valves [6,7],-grippers [8,9],-wrappers [10],-cages [11],-mirrors [12] and bi-stable actuators for tactile displays [13].…”

Section: Introductionmentioning

confidence: 99%

High-throughput study of martensitic transformations in the complete Ti–Ni–Cu system

et al. 2012

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“…Different micro-devices, such as micro-grippers, micromirrors and micro-cages have been designed and demonstrated using TiNi-based SMA thin films (Fu et al [12][13][14][15]. Concerns, however, remain for the applications of thin-film SMA materials, because of their unsatisfactory mechanical and tribological properties, chemical resistance and biological reliability, such as, potential nickel release [16,17] and poor localised corrosion in chloride containing environments [18,19].…”

Section: Introductionmentioning

confidence: 99%

Cyclic Nanoindentation and Nano-Impact Fatigue Mechanisms of Functionally Graded TiN/TiNi Film

Faisal

Prathuru

Goel

et al. 2017

Shap. Mem. Superelasticity

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The mechanisms of nanoscale fatigue of functionally graded TiN/TiNi films have been studied using multiple-loading cycle nanoindentation and nano-impact tests. The functionally graded films were sputter deposited onto silicon substrates, in which the TiNi film provides pseudo-elasticity and shape memory behaviour, while a top TiN surface layer provides tribological and anti-corrosion properties. Nanomechanical tests were performed to investigate the localised film performance and failure modes of the functionally graded film using both Berkovich and conical indenters with loads between 100 lN and 500 mN. The loading history was critical to define film failure modes (i.e. backward depth deviation) and the pseudo-elastic/shape memory effect of the functionally graded layer. The results were sensitive to the applied load, loading mode (e.g. semi-static, dynamic) and probe geometry. Based on indentation force-depth profiles, depth-time data and post-test surface observations of films, it was concluded that the shape of the indenter is critical to induce localised indentation stress and film failure, and generation of pseudo-elasticity at a lower load range. Finite-element simulation of the elastic loading process indicated that the location of subsurface maximum stress near the interface influences the backward depth deviation type of film failure.

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A shape memory microcage of TiNi/DLC films for biological applications

Cited by 34 publications

References 21 publications

Fabrication and Characterization of Nitinol-Copper Shape Memory Alloy Bimorph Actuators

Fabrication and Characterization of Nitinol-Copper Shape Memory Alloy Bimorph Actuators

High-throughput study of martensitic transformations in the complete Ti–Ni–Cu system

Cyclic Nanoindentation and Nano-Impact Fatigue Mechanisms of Functionally Graded TiN/TiNi Film

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