Soft Gripper with Adjustable Microspines for Adhering to Tree Branches

Abstract

Labour and resource intensive data collection methods drive the use of unmanned aerial vehicles in the field of environmental monitoring. UAV supported sensor deployment in forests can improve localized and continuous monitoring. To advance this field, we present a two fingered gripper with spines integrated on three phalanxes. The softness of the fingers combined with compliantly-supported microspines integrated into adjustable microspine-clusters allow the gripper to wrap and adhere to tree branches. With a differential drive actuation, microspine cluster adjustability as well as load-sharing between spine clusters is achieved. We characterize the bending behaviour of the soft fingers that adapt to curved and irregular objects. We show that the implementation of compliantly-supported and adjustable microspine-clusters increase holding force and that load-sharing between spine clusters is achieved with the differential drive actuation. The demonstration of UAV perching on a tree branch with the gripper shows that sensor deployment in these environments can be achieved.