An actuator assembly and method for making and using an actuator assembly. In one embodiment, the assembly includes an actuator body having an actuator channel with a first region and a second region. An actuator is disposed in the actuator channel and is movable when in a flowable state between a first position and a second position. A heater is positioned proximate to the actuator channel to heat the actuator from a solid state to a flowable state. A source of gas or other propellant is positioned proximate to the actuator channel to drive the actuator from the first position to the second position. The actuator has a higher surface tension when engaged with the second region of the channel than when engaged with the first region. Accordingly, the actuator can halt upon reaching the second region of the channel due to the increased surface tension between the actuator and the second region of the channel.