A new concept of a linear smart actuator

This paper discusses the utilization of deflected flexible beams to amplify the displacement of a nickel titanium (NiTi) shape memory alloy (SMA) actuator and to provide linear motion. The actuator is composed of a SMA wire fixed eccentrically along a flexible beam dividing it into equally spaced segments. It is designed mainly to overcome the problem of limited displacement upon using SMA wires as actuators and also due to the high force provided by the shape memory alloy wire upon heating. A preliminary testing for the actuator was performed which proves the benefit of using beam actuators to obtain longer amplified linear displacements. System identification techniques were used to model the SMA actuator upon heating and cooling. An ON/OFF control was applied to the actuator using the identification models, which showed closeness between simulation and experimental results.