Tough hydrogels for soft artificial muscles.

Mimicking the natural actuating systems artificially provides ample opportunities in the field of soft robotics. In this domain, recent advancements in tough hydrogels along with advanced manufacturing techniques have offered us new tools for creating hybrid and soft artificial muscles that resemble the attributes of natural muscles and biological organisms. This review article provides a summary of the recent developments in the field of hydrogel-based actuators and soft artificial muscles and presents a current account of their emerging applications. Further, the fundamentals behind the actuation of hydrogels are discussed with a focus on hydrogels swelling, diffusion, and mechanical behaviour. The design details of different tough hydrogel systems are highlighted, and their physical and mechanical properties are quantitatively compared with biological tissues. Finally, a brief conclusion is provided with remarks on the remaining challenges in this field. [Display omitted] • In-depth overview of hydrogel-based actuators, focusing on their fundamental attributes necessary for robotic systems. • Providing a comprehensive comparison between tough hydrogels and soft tissues as a selection guide for soft robotics. • Details of the new ground-breaking innovations taken place in the field of soft robotic systems based on tough hydrogels. [ABSTRACT FROM AUTHOR]