Muscle-inspired soft robots based on bilateral dielectric elastomer actuators

Muscle groups perform their functions in the human body via bilateral muscle actuation,which brings bionic inspiration to artificial robot design.Building soft robotic systems with artificial muscles and multiple control dimensions could be an effective means to develop highly controllable soft robots.Here,we report a bilateral actuator with a bilateral deformation function similar to that of a muscle group that can be used for soft robots.To construct this bilateral actuator,a low-cost VHB 4910 dielectric elastomer was selected as the artificial muscle,and polymer films manufactured with specific shapes served as the actuator frame.By end-to-end connecting these bilateral actuators,a gear-shaped 3D soft robot with diverse motion capabilities could be developed,benefiting from adjustable actuation combinations.Lying on the ground with all feet on the ground,a crawling soft robot with dexterous movement along multiple directions was realized.Moreover,the directional steering was instantaneous and efficient.With two feet standing on the ground,it also acted as a rolling soft robot that can achieve bidirectional rolling motion and climbing motion on a 2°slope.Finally,inspired by the orbicularis oris muscle in the mouth,a mouthlike soft robot that could bite and grab objects 5.3 times of its body weight was demonstrated.The bidirectional function of a single actuator and the various combination modes among multiple actuators together allow the soft robots to exhibit diverse functionalities and flexibility,which provides a very valuable reference for the design of highly controllable soft robots.

Origami-inspired folding assembly of dielectric elastomers for programmable soft robots

Origami has become an optimal methodological choice for creating complex three-dimensional(3D)structures and soft robots.The simple and low-cost origami-inspired folding assembly provides a new method for developing 3D soft robots,which is ideal for future intelligent robotic systems.Here,we present a series of materials,structural designs,and fabrication methods for developing independent,electrically controlled origami 3D soft robots for walking and soft manipulators.The 3D soft robots are based on soft actuators,which are multilayer structures with a dielectric elastomer(DE)film as the deformation layer and a laser-cut PET film as the supporting flexible frame.The triangular and rectangular design of the soft actuators allows them to be easily assembled into crawling soft robots and pyramidal-and square-shaped 3D structures.The crawling robot exhibits very stable crawling behaviors and can carry loads while walking.Inspired by origami folding,the pyramidal and square-shaped 3D soft robots exhibit programmable out-of-plane deformations and easy switching between two-dimensional(2D)and 3D structures.The electrically controllable origami deformation allows the 3D soft robots to be used as soft manipulators for grasping and precisely locking 3D objects.This work proves that origami-inspired fold-based assembly of DE actuators is a good reference for the development of soft actuators and future intelligent multifunctional soft robots.