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

Abstract

Shape memory alloys (SMAs) are a group of metallic alloys capable of sustaining large inelastic strains that can be recovered when subjected to a specific process between two distinct phases. Regarding their unique and outstanding properties, SMAs have drawn considerable attention in various domains and recently became appropriate candidates for origami robots, that require bi-directional rotational motion actuation with limited operational space. However, longitudinal motion-driven actuators are frequently investigated and commonly mentioned, whereas studies in SMA-based rotational motion actuation is still very limited in the literature. This work provides a review of different research efforts related to SMA-based actuators for bi-directional rotational motion (BRM), thus provides a survey and classification of current approaches and design 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’ design methods, sensing, and controlling strategies are discussed. Finally, open challenges are discussed.

Machine learning-based self-sensing of the stiffness of shape memory coil actuator

“…The electrical resistance of Shape memory coil changes when it regains its original (parent) shape, and this was proved during 1990 (Hu et al 2021). This change in Electrical resistance property leads to development of shape memory coil (SMC) as a sensor during actuation.…”

“…The resistance change can be used to monitor the phase transformation and improve the robustness of heat disturbance to avoid overheating of SMA spring. So, the stiffness and resistance are linearly dependent and can be used to directly control the stiffness (Hu et al 2021 ). The self-sensing modeling and investigations of stiffness characteristics of SMA spring are analyzed.…”

Control Aspects of Shape Memory Alloys in Robotics Applications: A Review over the Last Decade

“…The papers that reported or designed and developed SMA-based soft robots are presented (in chronological order) in the Table 1 which displays the control handle and the parameters that are measured for the particular application. 1 Pulse Width Modulation, 2 Proportional-Integral Derivative, 3 Bang Bang and Interative Learning, 4 Path Planning, 5 Bang bang, 6 Compressing Compensating Algorithm, 7 Bilinear Proportional Integral Derivative, 8 Motion Planning and Greedy Planning Algorithm.…”

“…However, there are complex systems, like when using to an instrument in higher-order systems it demands a nonlinear control for performance and efficacy at higher rates. With a wide understanding of the inherent characteristics, there has been immense growth in terms of literature reports and commercial growth [1][2][3][4][5][6][7]. Position control in shape memory alloy (SMA) has been researched only in the last two decades and it has been growing in different areas starting from the design and development of a servo type of operation using the aSMA element in different configurations and by using different biasing elements.…”

Modeling and Position Control Simulation Research on Shape Memory Alloy Spring Actuator

“…At present, new actuators include the piezoelectric actuator, shape memory alloy, ionic polymer actuator, magnetostriction actuator, electrostatic actuator, bimetallic actuator and so on [1]. The SMA actuator uses the shape memory effect and the mechanical characteristics of the weak martensite phase at room temperature and the strong austenite phase at high temperatures to perform external work [2]. Compared with other new actuators, the SMA actuator is widely used because of its advantages of a low driving voltage, large driving force, no noise and high power-to-weight ratio.…”