【作者】 李楠楠；

【导师】 董旭峰；

【作者基本信息】 大连理工大学 ， 材料学， 2021， 硕士

【摘要】 软体机器人具有良好的形态适应性,已成为涉及材料、机械、力学等多学科交叉的前沿领域。软体变形材料是软体机器人开发的材料基础,然而受一般软材料固有低模量属性的限制,目前的软体机器人普遍存在难以维稳、负载能力差等缺点。现有的解决方案是采用气动驱动器来赋予软体机器人以变刚度功能,但存在系统复杂、响应慢等问题。若能直接通过电场调控软体材料的弹性模量,开发出电驱动的变形-变刚度一体化智能材料,则有望解决制约软体机器人发展的瓶颈问题。介电弹性体（Dielectric Elastomers,DE）是典型的电致变形材料,被广泛应用于软体机器人领域;而另一种电致智能材料—电流变弹性体（Electrorheological elastomers,ERE）因其独特的电致变模量等特性被应用于变刚度减振装置的开发中。本文将电流变弹性体与介电弹性体有机结合,构建一种兼具电致变形与电致变模量双功能的介电流变弹性体复合材料（Dielectric Electrorheological Elastomer,DERE）,为新型刚度可控型软体机器人的开发奠定材料基础。首先,以尿素改性Ti O₂颗粒为填充相制备电流变弹性体,并对其电致粘弹性、电致变形效应进行研究。电致粘弹性测试结果表明,在0～3k V/mm的外加电场下,电流变弹性体储能模量随电场强度增大而增大,在3k V/mm的电场强度下时相对电流变效应达到12%。电致变形测试结果表明,电流变弹性体具有显著的电致变形能力,在电场强度为3k V/mm时,电流变弹性体的形变量比纯硅橡胶的形变量提高2.8倍。构建基于电流变弹性体的悬臂梁结构,在不同外加电场下测试其刚度的变化,结果表明电流变弹性体悬臂梁结构的刚度随场强的增加而增加。继而,将电流变弹性体与商用介电弹性体VHB4910层叠复合、并涂覆柔性电极,制备介电流变弹性体（DERE）。对DERE与VHB4910的电致变形行为和电致粘弹性、循环使用稳定性、蠕变回复等进行测试。实验结果表明,DERE的电致变形效应较VHB4910提升了20倍,且具有显著的电流变效应:在3k V/mm电场下,其剪切储能模量较零场下增长了11%;蠕变回复测试结果表明,在相同应力下DERE产生的蠕变应变更小,撤去应力后DERE的残余应变更小;多次定伸循环后的拉伸测试结果表明,DERE多次加载后的力学性能较单层VHB4910更为稳定。最后,设计并制作基于DERE的软体驱动器,测试结果表明,该驱动器具有显著的电控变形能力。更多还原

【Abstract】 Soft robots have good morphological adaptability and have become a frontier field involving materials,machinery,mechanics and other interdisciplinary fields.Soft deformation materials are the foundation of soft robot development.However,due to the inherent low modulus of soft materials,soft robot is difficult to maintain stability and poor load capacity.The existing solution is to use pneumatic actuator to give the soft robot a variable stiffness function,but there are problems such as complex system and slow response.If the elastic modulus of the soft material can be directly controlled by the electric field,and the integrated intelligent material of deformation and variable stiffness driven by electricity can be developed,the bottleneck problem restricting the development of the soft robot can be solved.Dielectric elastomers（DE）are typical electro-deformable materials,which are widely used in the field of soft robots.While another electro-intelligent material-electrorheological elastomers（ERE）is used in the development of variable stiffness vibration damping devices due to its unique characteristics of electrorheological modulus.In this paper,electrorheological elastomers and dielectric elastomers are combined to construct a dielectric electrorheological elastomer（DERE）with both functions of electro-deformation and electro-variable modulus.It lays a material foundation for the development of new type soft robot with controllable stiffness.Firstly,the electrorheological elastomer was prepared with urea modified Ti O₂ particles as the filling phase,and its electro-viscoelastic and electro-deformation effects were studied.The electro-viscoelasticity test results showed that under the applied electric field of 0～3k V/mm,the storage modulus of the electrorheological elastomer increased with the increase of the electric field strength,and the relative ER effect reached 12%under the electric field strength of 3k V/mm.The result of electro-deformation test showed that the ERE has significant electro-deformation ability.The shape variable of the ERE is 2.8 times higher than that of silicone rubber at the electric field strength of 3k V/mm.The cantilever beam structure based on electrorheological elastomer was constructed,and the change of its stiffness was tested under different applied electric fields.The result showed that the stiffness of the cantilever beam structure of electrorheological elastomer increased with the increase of voltage.Then,dielectric electrorheological elastomer was prepared by laminating ERE with commercial dielectric elastomer VHB4910 and coated with flexible electrode.The electro-deformation behavior,electro-viscoelasticity,recycle stability and creep recovery of DERE and VHB4910 were tested.The experimental results showed that the electro-deformation effect of DERE is 20 times higher than that of VHB4910.And DERE had a significant electrorheological effect:under the electric field of 3k V/mm,the shear storage modulus of DERE was increased by 11%compared with that of zero field.The creep recovery test results showed that the creep strain generated by DERE was small under the same stress,and the residual strain of DERE was small after the stress is removed.The tensile test results after repeated constant extension cycles showed that the mechanical property of DERE after multiple loading was more stable than that of single-layer VHB4910.The creep recovery test results showed that the creep stress of DERE is smaller under the same stress,and the residual stress of DERE is small after the stress is removed.Finally,a soft driver based on DERE was designed and manufactured.The test results show that the driver has remarkable electronic control deformation ability.更多还原