The actuator sits on top of a substrate that has a thin insulating dielectric layer on top. A voltage is applied between the actuator and the substrate, and the resulting potential pulls the body of the actuator downwards. When this occurs, the brush is pushed forwards by a small amount, and energy is stored in the strained actuator. When the voltage is removed, the actuator springs back into shape while the bushing remains in its new position. By applying a pulsed voltage, the SDA can be made to move forward.