A NOVAL DESIGN OF SHAPE-MEMORY ALLOY ACTUATED GRIPPERS

Given the increasing requirements for enhanced performance, accuracy, space efficiency and complexity in industry, there is a need for robots and industrial grippers to become faster, lighter, and more precise. Moreover, due to various reasons including energy efficiency concerns, there is a growing demand for compressed air-free production or, at the very least, severely curtailed compressed air usage. To address this challenge, this paper introduces a novel approach for industrial grippers that employs shape memory wires, leveraging injection molding automation as a specific use case. Three different concepts of implementing a gripping mechanism were developed, considering the functional and structural degradation of shape memory wires during the design process to meet the requirements throughout its entire cyclic lifetime. Subsequently, a characterization study was conducted on the manufactured gripper system to evaluate its performance. To enable a comprehensive evaluation, a control strategy was devised prior to the study, with the objectives of preventing thermal overheating, enhancing dynamics, and achieving a substantial reduction in power consumption.