Origami Flexiball-inspired Soft Robotic Jellyfish

With the accelerated development and exploration of the ocean,underwater robotics has received unprecedented attention and development as the most important means for human exploration of the ocean.Among them,the bionic design based on marine organisms and the design based on origami structures are both effective methods to solve robot design problems.In response to the current shortcomings of biomimetic jellyfish robots,such as complex structures,complex production processes,high production costs,and low propulsion efficiency.Based on the structure of rhombic dodecahedron origami flexiball and rhombic triacontahedron origami flexiball,the manufacturing methods of two kinds of origami flexiball structures are improved.On the basis of removing some materials from the two kinds of origami flexiballs,two kinds of origami flexiball variants that may be used to make the propulsion structure of the bionic jellyfish robot are proposed.The hydrodynamic performance of different origami flexiball structures is analyzed by computational fluid dynamics method,and a structure suitable for making bionic jellyfish robot-rhombic triacontahedral origami flexiball structure is determined.The core of the biomimetic jellyfish robot inspired by the developed origami flexiball is to use the deformation and structural elasticity of the origami structure to simulate the jet propulsion of jellyfish.Through the analysis of the deformation process of origami structure,the mathematical model of the jet propulsion of the bionic jellyfish robot inspired by the origami flexiball was established.The change of thrust force under different nozzle diameters and the relationship between the vortex ring formation nimber under different nozzle diameters and the thrust were analyzed through computational fluid dynamics,and the key structural parameters were determined.Secondly,the overall design of a biomimetic jellyfish robot inspired by origami flexiball was completed,and the basic components of the origami structure were printed using a 3D printer and bonded together in a certain order to form the origami flexiball structure.The biomimetic jellyfish robot inspired by the origami flexiball can be controlled by a motor to tighten the driving rope,thereby controlling the contraction of the origami flexiball structure,causing the nozzle to spray water and push itself forward.The driving rope is released by the motor to reverse and rely on the elasticity of the origami flexiball structure to restore its original shape and complete water absorption.Finally,the motion and propulsion capabilities of the biomimetic jellyfish robot inspired by the origami flexiball were verified through experimental analysis.The developed biomimetic jellyfish robot has advantages such as a maximum volume change rate of 48.98%,an average motion speed of 11.58 mm/s,and a peak propulsion force of 35.2 m N.Compared with the same type of rope driven robot,it has a transportation energy cost as low as 19.02,and the actual thrust force is better consistent with the simulation results of computational fluid dynamics.In summary,this article proposes a biomimetic jellyfish robot inspired by origami flexiball,and develops a prototype of the biomimetic jellyfish robot.A scheme has been proposed for a biomimetic jellyfish robot with low production costs and efficient propulsion.