Comparison of hydraulic microactuator configurations

摘要

New industrial and medical applications require microactuators with a high force and power density. During the last decades, it was believed that electrostatic and electromagnetic microactuators would fulfill these needs. However, recent research revealed that fluidic microactuators develop higher power and force densities at microscale. Despite these promising properties, hydraulic actuators are rare in microsystems technology. This paper presents and compares three actuator configurations that are particularly suitable for miniaturization. More precisely, this paper compares an artificial muscle microactuator with two piston type microactuators. Typical dimensions of the actuators are an outside diameter of 1.5 mm and a length of 15 mm. Measurements showed that force densities of more than 4 N/mm~2 and work densities of 0.4 mJ/mm~3 can be achieved at a driving pressure of 600 kPa. This is a magnitude higher than reported for typical electrostatic actuators; furthermore these characteristics can still be improved since the maximum driving pressure of the actuators has not yet been determined.