Development of a Spiral Shaped Soft Holding Actuator Using Extension Type Flexible Pneumatic Actuators

Recently, several pneumatic soft actuators have been applied to wearable and welfare devices to provide nursing care and physical support for the elderly and disabled. In this study, as a wearable soft actuator for holding body, a spiral shaped soft holding actuator that can wrap a user according to their body shape was proposed and tested. The construction and operating principle of the tested soft actuator with circumferential restraint mechanism using three extension type flexible pneumatic actuators (EFPAs) has been discussed. As a result, it was found that the tested actuator could hold elbows and knees when the joint is in motion. An analytical model of the spiral actuator was also proposed to achieve an optimal design. It can be confirmed that the proposed analytical model can predict the shape of the actuator when various EFPAs are pressurized.