A novel device was developed to amplify the travel of a solid state ceramic actuator using hydraulics. The principle of differential areas of pistons was used to increase actuator travel at the expense of actuation force.

The hydraulic amplifier consisted of an input piston, an output piston, and a common cylinder body in which were machined two connected cylinders. Each piston was sealed by an elastomer o-ring, and the two pistons were connected by a column of low-compressibility fluid. The theoretical gain of the amplifier, determined by the ratio of cylinder bore cross sectional areas, was 3.73.

Sources of loss were identified as compression of the working fluid, distortion of the o-rings, and compression of air that was trapped in the cylinder. A means was developed to estimate the relative magnitude of each type of loss.

A prototype was constructed. Losses were measured and found to be consistent with losses predicted by theory. Based on these measured losses, the output travel of a specific piezo-actuator amplified by the prototype was predicted.

Travel was predicted for a specific piezo-actuator amplified by many different hypothetical amplifiers of higher gains. Results showed strong potential for future hydraulic amplifiers to produce larger travels from solid state actuators while maintaining actuation forces in excess of those currently produced by other amplified actuators.