磁致链化对磁流变弹性体压阻效应的影响

Effects of particle pre-orientation via application of magentic field on the piezoresistivity of magnetorheological elastomer

为研究磁流变弹性体(Magneto-Rheological Elastomer,MRE)压阻效应机制及其影响因素,基于场致发射效应机制,结合均匀型与磁致链化型MRE结构特点,分别建立了两类镍粉填充液态硅橡胶型MRE的导电模型,得出了相应的MRE端面电阻表达式,分析了镍粉质量分数、测试电压对两类MRE阻值的影响;在零场下制备了均匀型MRE,在匀强磁场下制备了磁致链化型MRE,对两类MRE的压阻特性进行了系统测试;通过分析比较两类MRE的正压力与电阻对数的映射关系,验证了理论模型的合理性;相比于均匀型MRE样品的高阻抗和较小的阻值变化范围,在0~6kPa压力下,磁致链化型MRE样品阻值变化区间为10~106Ω,在触觉传感应用中具有更好的适用性。

To investigate the piezoresistivity mechanism and the influence factors of magneto-rheological elastomer（MRE）,the conduction models and resistance expressions of isotropic and anisotropic MREs were established respectively based on their structural characteristics and the field emission theory.Further,the effects of Ni filler concentration in silicone rubber and applied voltage on the resistance were analyzed.Experiments were carried out to study the piezoresistive properties of the two MREs.MRE samples with isotropic（prepared without magnetic field）and anisotropic（pre-orientated with a magnetic field）distributions of Ni powders were prepared,respectively.The two conduction models were verified through comparison of the mapping relationships between the experimental pressure and the logarithmic resistance data.In comparison with the high impedance and low resistance range of the isotropic MRE,the anisotropic MRE changes from 106Ωunder 0kPa to 10Ωunder 6kPa,which presents a better feasibility in tactile sensing applications.