Actuators

Piezoelectric Materials

Chapter contributed to the book Smart Technologies, World Scientific.

Piezoelectric modelling for an impact actuator

Amplification techniques for piezoelectric actuation are briefly reviewed and an unlatching impact piezo-actuator then proposed. In such a device, a piezoelectric multilayer has the function of imparting kinetic energy to a mass connected to an …

Piezoelectric actuators in micropositioning

Micromachines can be built only with the aid of other machines that have micropositioning abilities. Fast and precise positioning devices are needed to increase reliability and speed in the production of the miniaturized devices. Intensive research …

Unlatching Piezoelectric Actuators

Piezoelectric multilayer actuators have long established their supremacy in precise positioning applications. Apart from very accurate position control, piezoelectric actuators provide fast actuation with low energy requirements; these valuable …

Distributed mass modelling of piezoelectric multilayer actuators in Matlab Simulink

A Matlab Simulink model is presented, where the constitutive equations of piezoelectricity are implemented in a distributed mass scheme. The model comprises two main sub-systems (mechanical and electrical) and their interaction. The electrical part …

Piezoactuators for `real world' applications. Can they deliver sufficient displacement?

Piezoelectric actuators can develop large forces very quickly and with high efficiency. The need for high-voltage power supplies has been overcome with stack or multilayer actuators, but the available displacements are still minute. This has limited …

Dynamic characteristics of piezoelectric multilayer stack actuators

Piezoelectric actuators have found many applications in mechatronics systems because of their ability to provide large forces in very short times. To overcome the limits of the tiny displacements available, different amplification mechanism have been …

The Electrical Transport Properties of Shape Memory Alloys Under a Stress State

The electrical resistance of shape memory alloys under an increasing stress state is here examined: the relevance of the transformation strain connected with the stress induced transformation and the concomitant electronic resistivity change at the …

The electrical resistance of Ni(50)Ti(30)Hf(20) and Ni(50)Ti(40.5)Hf(9.5) melt-spun ribbons during current-driven thermal cycles

The electrical resistance of Ni50Ti30Hf20 and Ni50Ti40.5Hf9.5 alloys during stress assisted two way memory effect was investigated with the aim to deduce the relationship between electrical resistance and deformation across the transformation range. …

The electrical transport properties of shape memory alloys

The effectiveness of shape memory alloys as active elements in thermal actuators is proved by the huge amount of applications developed in the last few decades. In recent years, interest has kept growing in the sensing capabilities that they show …