A novel Shape Memory Alloy (SMA) actuator consisting of a number of thin NiTi bers woven in a counter rotating helical pattern around supporting disks is rst described. This structure can be viewed as a parallel mechanism used to accomplish a highly e cient transformation between force and displacement. The actuator overcomes the main mechanical drawback of shape memory alloys, that being limit...

The nickel-titanium (Ni-Ti) alloys used in endodontics contain 56% Ni and 44% Ti. The 2 unique features related to clinical dentistry (i.e., shape memory effect and superelasticity) are due to the transition from austenite to martensite in Ni-Ti alloy. When a superelastic Ni-Ti alloy undergoes a low tensile loading, normal elastic behavior occurs. In fact, at higher tensile loads, the elastic s...

A novel Shape Memory Alloy (SMA) actuator consisting of a number of thin NiTi bers woven in a counter rotating helical pattern around supporting disks is rst described. This structure can be viewed as a parallel mechanism used to accomplish a highly ee-cient transformation between force and displacement. The actuator overcomes the main mechanical drawback of shape memory alloys, that being limi...

This study aimed to reveal the interface behavior of iron-based shape memory alloy (Fe-SMA) strips bonded metallic substrates in order ensure integrity such joints. A series single lap-shear tests was performed on Fe-SMA-to-steel adhesively The test results that bond strength can reach over 70% tensile Fe-SMA and cohesive failure mode be realized. It is identified three energy dissipation mecha...

Employing the Ginzburg-Landau phase-field theory, a new coupled dynamic thermo-mechanical 3D model has been proposed for modeling the cubic-to-tetragonal martensitic transformations in shape memory alloy (SMA) nanostructures. The stress-induced phase transformations and thermo-mechanical behavior of nanostructured SMAs have been investigated. The mechanical and thermal hysteresis phenomena, loc...

This paper presents the construction of a six-legged bio-mimicking robot. The mechanical design includes the actuation design based on shape memory alloy (SMA) actuators and the locomotive mechanism. The motion control system implements various gaits for the robot to maneuver. The sensors used in the control system include the accelerometer, the compass sensor and the step sensors. We develop a...

The essential steps and issues in the development of a Shape Memory Alloy (SMA) based multi-degrees-of-freedom monolithic manipulator are reflected upon. The use of Direct Metal Deposition (DMD) will be described for the manufacture of the manipulator’s structure followed by the exploration of the feasibility of the “self-sensing” functionality of the structure as a basis for the manipulator’s ...

Endoscopic surgery has recently been adopted in various surgical operations. Forceps stuck through trocars into the abdominal or chest cavity, dissects and grasps internal organs. Due to their xed shapes, the current forceps limit the skill of surgeons. We have worked on the development of active forceps adoping shape-memory-alloy pipes and coaxicially assembling them. In this paper, we show se...

In this paper, closed loop nonlinear control of a shape memory alloy (SMA) actuated flexible needle is presented. Merits of different modalities of sensory feedbacks are studied. In order to track the given desired trajectory, the actual position of the needle tip is controlled using three different feedback signals (i) Vision, (ii) Electromagnetic (EM), and (iii) Ultrasound (US) imaging feedba...

This paper proposes the controller design for a shape memory alloy (SMA) positioning actuator system. The system utilizes spiral-formed SMA wire as driving power source. generates force via temperature-based crystalline phase transitions. is deformed in spiral form under low temperature and heated by applying direct current, it recovers to original recovering force, which rotates attached load....