Advancements in Ionic/Electroactive Materials and Structures for Soft Robotics

Dielectric elastomers and hydrogels possess some special physical and chemical properties, and respond well to external stimuli, which make them important components of new soft actuators, wearable devices, medical healthcare equipment, and human-machine interactive robots. This article firstly explores the application prospects and improvement paths of electronic-type electroactive polymers, i.e. dielectric elastomer materials. By discussing the performance, advantages, and disadvantages of silicon rubber, polyurethane, and acrylic ester-based dielectric elastomers, the current application potential and limitations of these materials in artificial muscles are elucidated. Subsequently, some solutions are proposed, including the use of brush-like dielectric elastomers (BBE) and interpenetrating network structures (IPN) to enhance material performance. Secondly, electromagnetic-responsive, osmotic-pressure-responsive, and photo-responsive hydrogel actuators are introduced, providing comprehensive explanations of their respective working principles and applications. Finally, the impacts of both dielectric elastomers and hydrogels as two types of driving materials and structures on soft robotics performance are summarized, and the broad application potentials of these two types of actuators are showed in areas such as soft robotics, artificial muscles, and intelligent sensors, and some future research directions are suggested.