Research On The Shape-Deforming And Sensing Capabilites Of Magnetic Actuated Soft Robots Based On The NdFeB/Polymer Composites

Magnetic actuated soft robots are a kind of robot composed of flexible composites with magnetic response deformation capability.Under non-contact control of magnetic field,several functions such as continuous deformation,free locomotion and items transportation have been rendered to magnetic actuated soft robots.Attributing to their secure humanmachine interaction and excellent environment adaptability,magnetic actuated soft robots hold broad promise for many applications including biomedical science,environmental exploration and industrial production,leading to a hotspot in the field of interdisciplinary and frontier exploration.The research of magnetic actuated soft robots is in its infancy,and the innovations in new materials,new methods and new ideas are emerging.At the same time,in terms of research methods,design optimization and function realization,the following problems still remain to be solved:(1)The mathematical model of the magnetic actuated soft robots deformation problem is not fully clarified,and the application of the numerical simulation method is insufficient,(2)the limited shrinkability of robots restrict their application in constrained environments,and(3)the lack of combined sensing and shape-deforming capabilities restricts their adaptation to the changing environments.In view of above problems,the following exploration and research are carried out in this thesis:(1)A mathematical model for shape-deforming of magnetic actuated soft robots is established,and effects of the robots’ magnetic powder content and structure on their deformation ability are analyzed,providing guidance for the design of magnetic actuated soft robots.Combining experimental measurements and curve fitting,the magnetic and mechanical constitutive relations of Nd Fe B/Ecoflex magnetic soft composites are studied,so as the mathematical model of the magnetic actuated deformation problem.Based on that,numerical simulation method is introduced to further study the influence of structure and material parameters on the deformation of magnetic soft robots.The results show that the magnetic robots with 60 wt% magnetic powder contents have good deformation capabilities,and these capabilities gradually increase with the decrease of the robot thickness.(2)Through structure and magnetization method design,the considerable shrinkage deformation of magnetic actuated soft robot is realized.A soft robot that can shrink greatly under the magnetic field is prepared through a special hollow corrugated pipe structure design.The robot can transport items to the target position along a stated direction in threedimensional space.Furthermore,in order to improve environmental adaption of magnetic actuated soft robots,a multi-pole distributed hollow spherical structure soft robot is designed,which can realize considerable shrinking and free movement in the amphibious environment.Owing to the excellent shrinkability,the spherical robot with a diameter of 40 mm can squeeze through a narrow slit with a height of 8 mm,or a channel with a height of15 mm.Combining the excellent constrained movement with items transportation capability,the soft robot can carry 20 elastic pellets of 6 mm in diameter through a slit half of its height,then release these elastic pellets to the designated area under the control of magnetic field.(3)Combining the flexible magnetoelectric sensor and the magnetic shrinkable structure,the integration of sensing and shape-deforming capabilities for the magnetic actuated soft robot is realized.Inspired by the actively sensing and shape-deforming of sea anemones,a sensing-deformation integrated soft robot composed of bionic soft sensing tentacles and bionic shrinkable body is prepared.The robot can detect water flow velocity information,thus to guide the deformation of its body.When the water flow velocity exceeds1.1 m/s,the sensing tentacles can inform the robot to shrink to avoid being swept away.When the water flow velocity turns to slow,the robot can extend its bionic body to restore its slender shape.By Abaqus numerical simulations,the influence of preparation parameters on the bionic body shrinkability is investigated.The results show that the bionic body has a good shrinkability when the magnetic particle content is 60 wt%,and the shrinkability increases with the decrease of bionic body thickness and the increase of bionic body wavelet depth coefficient.Based on the simulation results,the function of the bionic body is further optimized by tuning the material and structure parameters.The results show that a bionic body shrinkage ratio of 64% can be realized when the magnetic particle content is 60 wt%,the bionic body thickness is 0.6 mm and the bionic body wave depth coefficient is 0.2.