This paper introduces a high performance actuation mechanism to enable new systems and improve the performance and efficiency of existing systems. The concept described is based on coupling energy storage mechanisms with translational movement to increase the speed and controllability of linear actuators. Initial development is a high speed linear actuator for hydraulic proportional valves, and the concept can be extended into other applications. With high speed proportional valves, the performance of existing cam phasing systems can be improved or the actuation mechanisms can be applied directly to IC engine valve actuation. Other applications include active suspension control valves, transmission control valves, industrial and commercial vehicle fluid power systems, and fuel injection systems. The stored actuation energy (such as a rotating mass) is intermittently coupled and decoupled to produce linear or rotary motion in the primary actuator. This paper describes multiple means of coupling an energy storage source to control actuator motion including magneto-rheological fluids, piezoelectric actuators, electromagnetic solenoids, or electromagnetic interaction between moving components. The energy source can be an existing rotating shaft, a shaft driven by a small motor, or similar. Preliminary analysis calculating the potential of magneto-rheological fluid as the coupling mechanism has been completed and results are presented.