Magnetic Actuation Performance And Deformation Mechanism Of Magnetorheological Actuator

Magnetorheological actuator with high elasticity,high response rate and superior stiffiness adjustability has attracted increasing attentions for their potential applications in soft intelligent devices,bionic equipment and biomedical instruments,etc.In this paper,suitable magnetic particles and polymer matrix were fabricated to obtain a magnetorheological actuator with excellent magnetic responsive performance by optimizing the preparation process.As a result,the mechanical properties and actuation performance of magnetorheological actuator were significantly improved.Furthermore,a mechanism was performed to explain the deformation performance for magnetorheological actuator.The main contents of this paper are described as follows:1.Two core-shell bidisperse magnetic particles based on micron carbonyl iron(CI)and Fe₃O₄ nanoparticles were dual-coated with gelatin,grapheme oxide(GO)and multi-walled carbon nanotubes(MWCNTs)through a sol-gel method.The microstructure characteristics of the magnetic particles were characterized.And the fundamental performance was measured and compared in terms of the magnetization performance,rheological properties and dispersion stability.The suitable magnetic particles were selected for the dispersion phase of magnetorheological actuator.2.The magnetorheological actuator based on porous magnetic AL-GE sponge matrix was constructed through a freeze-drying method.The experimental methods were established for mechanical properties and magnetic actuation performance of the magnetorheological actuator.And the evaluation method was introduced to the mechanical and magnetic actuation performance of magnetorheological actuator.Besides,the effects of sol concentration and plasticizer on the microstructure,viscosity and hardness were investigated,in which the influence mechanism was analyzed.3.The effects of gelatin and magnetic particles contents on the mechanical properties of magnetorheological actuator were obtained through the measurement of tensile performance,compressive performance and rheological perperties of the magnetostrictive component.The magnetic responsive performance of the actuator was studied using the test system under the effect of uniform and gradient magnetic fields.And the optimal process parameters of magnetorheological actuator were determined by analyzing the effects of gelatin contents,magnetic particles contents,area of action and test position on their magnetic actuation performance.4.The influence of magnetic flux density,gelatin,magnetic particles and MWCNTs contents on the magnetoelectirc properties was investigated for the magnetorheological actuator.As a result,the variational trends of the resistance characteristics were given for different magnetorheological actuators.And the repeatablility and recoverability of the resistance were tested to lay the foundation for real-time measurement and feedback control of the magnetic responsive displacement of actuators.5.The improved two-component lattice Boltzmann method with respect to the magnetostrictive component model was performed to simulate the rheologcial behavior,motion velocities of magnetic particles,and the microstructure evolution of the bidisperse system with different mass fractions of Fe₃O₄ nanoparticles under an external magnetic field.And the force applied on bidisperse magnetic particles was analyzed from mechanics.The reliability of the model was verified by SEM experiments.Furthermore,a mechanism from the microscopic angle was proposed to explain the magnetic responsive deformation for the magnetorheological actuator.