Flexible, Low-mass Robotic Arm Actuated by Electroactive Polymers and Operated Equivalently to Human Arm and Hand

Actuation devices are used for many space applications and there is increasing need to reduce their size, mass, cost and power consumption. To address this need, JPL is developing electroactive polymers (EAP) with emphasis on two EAP categories that induce large bending and longitudinal actuation strains. Comparison between EAP and the widely used transducing actuators shows that, while lagging in force delivering capability, these materials are superior in mass, power consumption and actuation strain levels. This study is concentrating on the development of effective EAPs and the enabling of mechanisms that employ their unique characteristics. Several EAP driven mechanisms that emulate human hand were developed including a gripper, manipulator arm and surface wiper. The manipulator arm is made of a composite rod that is lifted by a longitudinal rope actuator and has an end-effector gripper with bending EAP fingers allowing to grab and hold such objects as rocks. The EAP surface wiper operates like a human finger and can be used to remove dust from windows and solar cells. These EAP driven devices take advantage of the large displacement capability with less concern for their limited force actuation capability.