SMASH is a research and development effort funded by DARPA in which CSA is developing a new class of compact hybrid actuators for use in aircraft and other applications. By combining smart materials with hydraulic actuation, CSA will produce devices with performance that exceeds that of present-day actuators used in motion control. This program will produce both complete actuators and new component technology including fast acting smart materials based valves. As the research progresses, CSA is inserting elements of the new technology into other government systems and industrial products.

SMASH uses high energy density smart materials such as piezoelectrics operating at a high frequency to effect relatively large stroke devices at lower frequencies, up to about 50 Hz. The stiff, short-stroke smart materials pressurize hydraulic fluid directly, removing the need for the traditional central hydraulic supply and distribution lines. Through precise valve control, the fluid will be delivered to and removed from a hydraulic output stage, providing actuation for external mechanisms. SMASH devices will achieve bandwidths comparable to conventional devices, but at higher overall electromechanical efficiency. The concept is modular to allow customization for many different existing applications, and to enable new ones by exploiting unique properties of the SMASH actuators.

Present day hydraulic actuators typically rely on a central supply of high-pressure fluid. A servovalve is controlled to distribute this fluid to hydraulic output devices, where the pressurized fluid does useful mechanical work. While such actuators are effective in numerous applications, such as aircraft and submarines, benefits would accrue from higher efficiency devices and from eliminating the central hydraulic supply. By using inherently energetic smart materials to drive the fluid directly, the complexity of transduction is reduced. By operating in a closed fluid system, central fluid supplies and transfer lines are eliminated.

Applications targeted by this development begin with those currently employing hydraulic and ballscrew actuators as well as those that are not feasible because of limitations in present-day devices. Aerodynamic control surfaces, including control surfaces within engines, are a main application. Primary flight control actuators for missiles or non-conventional, uninhabited air vehicles (UAVs), and flow-control devices for marine and aerodynamic applications also fall within this scope. Self-contained compact devices developed by this program will also enable new classes of applications requiring high-authority actuation in small, portable packages. Examples include exoskeletons to extend the range of human strength, autonomous vehicles and biomimetic devices for exploration and action in hostile environments, and highly maneuverable, compact weapons systems.