Origami structures are highly demanded for engineering applications. Using origami folding to design and actuate mechanisms and machines offers attractive opportunities. In this paper, we design a crawling robot driven by pneumatic foldable actuators (PFAs) based on Miura-ori, according to the parallel foldable structure and different control patterns, which can perform different movements. The PFA inspired from Miura-ori is composed of a folding part, transition part, and sealing part, made by flexible materials and a paper skeleton. This actuator can obtain a large deformation by folding under negative pressure due to its own characteristics, and the relationship between deformation and pressure is analyzed. According to the different folding and unfolding times of left and right actuators, the crawling robot can perform both linear and turning movements. The speed of the robot is about 5 mm/s and it can turn at a speed of about 15°/s. The crawling robot uses the ability of the foldable structure to cope with the challenges of different environments and tasks.

The soft robot is a new type of robot with strong adaptability, good pliability, and high flexibility. Today, it is widely used in the fields of bioengineering, disaster rescue, industrial production, medical services, exploration, and surveying. In this paper, the typical driven methods, 3D printing technologies, applications, the existed problems, and the development prospects for soft robots are summarized comprehensively. Firstly, the driven methods and materials of the soft robot are introduced, including fluid driven, smart materials driven, chemical reaction driven, a twisted and coiled polymer actuator, and so on. Secondly, the basic principles and characteristics of mainstream 3D printing technologies for soft materials are introduced, including FDM, DIW, IP, SLA, SLS, and so on. Then, current applications of soft robots, such as bionic structures, gripping operations, and medical rehabilitation are described. Finally, the problems existing in the development of soft robots, such as the shortage of 3D printable soft materials, efficient and effective manufacturing of soft robots, shortage of smart soft materials, efficient use of energy, the realization of complex motion forms of soft robot, control action accuracy and actual kinematic modeling are summarized. Based on the above, some suggestions are put forward pertinently, and the future development and applications of the soft robot are prospected.

Dielectric elastomer (DE) is a soft material that can deform to a large degree under the action of an electric field. In this paper, multilayer DE films were stacked in parallel to prepare a 20-layer dielectric elastomer actuator (DEA). This DEA could provide a peak output force of 30 N, which significantly improves the driving performance of the DEA and provides conditions for large load driving of the DEA. As a new driving method, the DEA was applied to a jumping robot, and the heavy-weight robot accomplished jumping motion after several cycles of energy storage.