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...

Laser annealing of shape memory alloy thin films provides new opportunities in actuator design and fabrication for microelectromechanical systems applications. In this paper, we present a three-dimensional thermal model to simulate the crystallization process when a laser beam is swept across an amorphous NiTi thin film. Experimental crystallite nucleation and growth rates are included in the m...

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...

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...

A new electrode array embedded with nitinol shape memory alloy actuator has been designed so that it can be located beneath the basilar membrane inside the cochlear scala tympani to effectively deliver neurotrophins (growth factors) into the cochlea. The electrode array is also expected to be inserted deeper into the cochlear middle turn to stimulate further auditory neurons compared to the Nuc...

The two-way shape memory effect in a Ti36Ni49Hf15 high temperature shape memory alloy (SMA) has been systematically studied by bending tests. In the TiNiHf alloy, the martensite deformation is an effective method to get two-way shape memory effect even with a small deformation strain. When the TiNiHf alloy is deformed at a full martensite state, the deformation mechanism is the martensite orien...