Composite of thermally responsive solution and lubricating micro beads as sealing material for piston-cylinder actuator

In this paper, we propose a novel sealing technique for a piston-cylinder actuator. Pneumatic actuators, especially piston-cylinder actuators are attractive in MEMS field because of its high force density. The sliding part of the piston actuator requires both high sealing and excellent lubrication. We reported parylene deposition of a piston rod to improve sealing. In contrast, this paper presents a smart sealing material composed of thermally responsive solution and lubricating micro beads. Micro beads contributed to provide lubricant between a sliding part and an inner wall when thermally responsive solution gels by heating. Heated composite of thermally responsive solution and micro beads gels around a piston rod while the composite works as pressuring liquid in the region without heating. We evaluate piston cylinder of restriction force, pressure resistance, and force. We observe inside of piston cylinder actuator to understand detail phenomenon. Piston actuator is integrated with a heater.