Dexterous all-soft hand (DASH) with active palm: multi-functional soft hand beyond grasping

Abstract

Safety and adaptability are key features of anthropomorphic robotic hands and tend to receive significant attention, however, the motion of the palm, which is also an essential element of a dexterous hand, is often ignored. Not only does a rigid palm lack compliance, but its limited manipulative capacity restricts the soft anthropomorphic hand’s range of applications. Thus, in this study, we present the dexterous all-soft hand (DASH), featuring an active palm based on pneumatic actuation. The DASH is comprised of five fingers and an active palm with 11 degrees of freedom, which enable it to achieve a range of metacarpal motions as well as thumb opposition. A step-by-step casting method was used to fabricate the hand and a set of tests were performed to characterize the bending angle and the blocked force between fingers and palm. The ability of this novel hand to achieve the highest possible scores in the Kapandji test, the injection operation, scissors manipulation and unscrewing the cap was subsequently demonstrated. The DASH is the same size as an average adult female hand, and offers the additional benefits of light weight (165 g), low cost and ease of fabrication. Moreover, its manipulation ability further broadens the range of potential applications for this type of robotic hand.