Characteristics of a non-woven PVC gel actuator

In recent years, polymer actuators have been actively studied. Polyvinyl chloride (PVC) gel actuators contain PVC gel, which is PVC plasticized by dibutyl adipate, and is soft and light. A conventional PVC gel actuator consists of a mesh anode sandwiched between two PVC gel sheets that are flanked by foil cathodes. The PVC gel moves into the openings of the mesh electrode when it is charged, causing the unit structure to contract in the height direction. Such actuators exhibit about 10% contraction strain, 500-Pa recovery stress and 0.07-s response time at 100 V. However, a high applied voltage is dangerous near humans and a recovery stress of 500 Pa is weak for use as an artificial muscle. Thus, the applied voltage and recovery stress of PVC gel actuators need to be decreased and increased, respectively. To resolve these issues, we developed a new non-woven PVC gel actuator. Four kinds of non-woven PVC gel were fabricated to investigate the influence of fiber diameter and gel thickness on actuator performance. Displacement and contraction strain, recovery stress, and response time below 100 V were compared with those of a conventional PVC gel actuator. The developed actuators showed 20% contraction strain, which is twice that of a conventional actuator, 56.8-Pa recovery stress and 0.5-s response time. The fiber diameter influenced response time, while the thickness of the non-woven gel affected contraction strain, recovery stress and response time.