The effect of superposed transitions in actuators with layered shape memory alloy (SMA) films undergoing martensitic phase transformation is analyzed in terms of a model developed for two layers of different composition, deposited at the same temperature on a substrate. A significant difference is observed in the actuation versus temperature relationship, depending on the thermal and elastic pr...

This paper presents a micro-sized self-reconfigurable modular robotic system using shape memory alloy (SMA) actuators. Composed of identical robotic modules, the system can actively configure various structures. The motion of module is based on two-dimensional rotation by using an actuator mechanism with two SMA torsion coil springs. The micro-sized module measures 2cm cube and weighs 15g, half...

The blood ducts must be occluded to avoid loss of blood from vessels in laparoscopic surgeries. This paper presents a locking mechanism to be used in a ligation laparoscopic procedure (LigLAP I), as an alternative solution for a stapling procedure. Currently, stapling devices are being used to occlude vessels. Using these devices may result in some problems, including injury of bile duct, takin...

This paper proposes a magnetic actuator system of a new type capable of inspection in a complex pipe by means of a new motion principle. Using plural vibration components, the magnetic actuator is able to move in the complex pipe. A magnetic actuator of the reversible type, due to opening and closing of a compound material by using elongation and contraction of four shape-memory-alloy (SMA) coi...

This paper presents the results from an experimental study on the actuation response of composite laminates containing Shape-Memory Alloy (SMA) actuators. Unidirectional glassfibre reinforced epoxide laminates were constructed containing Ni-Ti SMA actuators orientated parallel to the glass-fibre direction. The volume fraction of actuator was varied in the range 0 to 2.5 ~ 0 1 % . These laminate...

We have developed two types of shape memory alloy (SMA) actuator and estimated the long-term reliability of SMA microcoils. A tube type tip articulator consists of 4 sets of SMA microcoil (wire diameter: 0.125 mm, coil diameter: 0.5 mm) for driving source and super elastic alloy (SEA) microcoils (wire diameter: 0.1 mm, coil diameter: 0.5 mm) for bias springs, support plates and flexible outer t...

The paper introduces a contribution in the design of adaptive controllers. A PID adaptive controller derived using the mathematical formulas of model reference adaptive control (MRAC) combined with the self tuning adaptive control (STC). The controller tested in the position control of shape memory alloy (SMA) wire and enhanced by experiment to an Enhanced adaptive controller which is more robu...

This paper describes two methodologies for increasing the actuation speed of the shape memory alloy (SMA) actuator in ambient environment. The first method involves the implementation of a simple, light-weight heat sink, which consists only of a combination of an outer metal tube with the silicone grease, but able to cool the heated alloy effectively. The second method describes a high current ...

Shape memory alloy (SMA) actuators can be made very compact and simple. An effective control algorithm is an integral part of every SMA actuator. This article presents a review of the state of the art research on control of SMA systems. It is worth noting that almost exclusively all control systems applied to SMA actuators are not model-based control algorithms. In other words, the control syst...