Design of a Morphing Compliant Mechanism With Separate Gripping and Retraction Modes Using a Single Actuation

Abstract

A key aspect of robotics and automation is continuous repetition of predefined travel and actions. One such example is a robotic gripper, gripping an object, retracting, and displacing it. Usually, two separate actuations are needed to implement the decoupled gripping and retraction modes. In this article, a morphing compliant gripper is proposed that grips an object (X displacement) and retracts it linearly (Y displacement) based on one single actuation, to reduce the input efforts. The mechanism is first designed by the rigid body replacement method and is based on the double-slider mechanism. Morphing is successfully achieved through the use of contact-aided features and a pseudo spring beam to decouple the X and Y displacements. The design is comprehensively analyzed through the nonlinear finite element analysis method and is optimized using the integrated design exploration tools. Simulation results closely match an ideal X and Y displacement path and a displacement-activated transition from X displacement to Y displacement while minimizing the input actuation force. Finally, a 3D-printed prototype is made and preliminarily tested to verify the design.