A Review of SMA-Based Actuators for Bidirectional Rotational Motion: Application to Origami Robots

Abstract

International audienceShape memory alloys (SMAs) are a group of metallic alloys capable of sustaining largeinelastic strains that can be recovered when subjected to a specific process between twodistinct phases. Regarding their unique and outstanding properties, SMAs have drawnconsiderable attention in various domains and recently became appropriate candidates fororigami robots, that require bi-directional rotational motion actuation with limitedoperational space. However, longitudinal motion-driven actuators are frequentlyinvestigated and commonly mentioned, whereas studies in SMA-based rotationalmotion actuation is still very limited in the literature. This work provides a review ofdifferent research efforts related to SMA-based actuators for bi-directional rotationalmotion (BRM), thus provides a survey and classification of current approaches anddesign tools that can be applied to origami robots in order to achieve shape-changing.For this purpose, analytical tools for description of actuator behaviour are presented,followed by characterisation and performance prediction. Afterward, the actuators’ designmethods, sensing, and controlling strategies are discussed. Finally, open challenges arediscusse