Design and characterization of linear shape memory alloy actuator with modular stroke

In this work a novel actuation system based on NiTi shape memory springs has been designed and characterized in a small-scale prototype to permit setting of the right aperture and its modulation when necessary. The manufactured prototype exploits an actuator in the antagonist configuration. In particular, the aim has been focused on the modulation of the stroke by the activation of Shape Memory Alloy (SMA) actuators. SMA springs of 15 turns and 7.5 mm average diameter are the optimal solution relatively to force and stroke required from the system. One of the possible applications of such actuator is in the field of solar reactors in which one of the main problem is to keep constant temperature into the reactor in order to allow a continuous and efficient transformation, from sunrise to sunset.