A shape memory alloy (SMA) actuator for engaging and actuating a device. The actuator includes an engagement mechanism, a bias element, and a SMA object(s). The SMA actuator may automatically and passively transfer to a backup or redundant feature that resets or extends the actuator's operational life. In one embodiment, the SMA actuator includes an additional SMA object(s) that replaces the primary SMA object(s) in the event the primary SMA object(s) breaks. The SMA actuator may also be configured to apply a dynamic stress to the SMA object during transition of the object to modify the transition temperatures of the object. The SMA actuator may be part of a fluid distribution system, such as a heating, ventilation, and air conditioning (HVAC) system and used to control the flow of fluid, such as air, from the distribution system.