Abstract: A hydraulic actuator is described which has a layered structure and a flattened piston assembly to enhance production speed and reduce the costs of assembly. A system for performing surgery is also described incorporating the hydraulic actuator, having a sensory glove, a computer, and a slender robot manipulator which can be inserted into the human body through a small incision. The robot manipulator has a layered structure with integrated hydraulic pistons. This design allows the use of a novel manufacturing process in which all of the parts are formed from laminated sheets of material. Seals are formed to prevent leakage of hydraulic fluid by introducing castable rubber into enclosed channels in the structure.