Development of gel-structured electro-rheological fluids and their application to nano positioning mechanism

电流变液是一种粘弹性随外加电场强度变化的功能流体。电流变液的特性被期望用来控制机械元件的性能，并已被应用于可变阻尼器和离合器等机械元件中。但电流变液的缺点是电流变颗粒的沉积和密封机制的要求。电流变颗粒的沉积降低了电流变效应，导致电流变器件的稳定性降低。为了解决这些问题，凝胶结构电流变液（ERG）的发展在这项研究中。由于凝胶的骨架阻止了ER颗粒的沉降，因此成功地抑制了ER颗粒从基础油中的分离和沉降。实验分析了ERG的基本特性。在基本分析结果的基础上，将ERG应用于纳米定位机构，并对其性能进行了评价。首先，实验研究了视网膜电图的组成成分与操作性能之间的关系。实验分析表明，在电场作用下，ERG产生的剪切应力是电流变液的20~30倍。ERG也显示了ER效应的高重复性。ERG的这些高性能表明，ERG中的ER效应的发生机制不同于ERF中的ER效应，其起源于颗粒链的形成。ERG的电流变效应源于ERG表面的摩擦条件随外加电场的变化而发生变化。在性能分析的基础上，将ERG应用于气动滑块夹紧机构。提出了基于ERG的零力夹紧机构。夹紧时滑块不产生误动，夹紧力电动调节。

Electro-rheological fluids (ERF) are functional fluids whose viscoelastic properties vary with the intensity of the applied electric field. The property of ERF has been expected to control the performances of machine elements, and the ERF has been applied to machine elements such as variable dampers and clutches. However, the disadvantages of ERF are the sedimentation of ER particles and the requirement of seal mechanism. The sedimentation of ER particles reduces the ER effects, results in low stability of ER devices. To solve these problems, gel structured electro-rheological fluids (ERG) were developed in this study. The separation and sedimentation of ER particles from the base oil were successfully suppressed because the frames of gel prevent the particles from sedimentation. The basic characteristics of ERG were experimentally analyzed. On the basis of the results of the basic analysis, ERG was applied to the nano positioning mechanism and their performances were evaluated. First of all, the relation between the constituents of ERG and the performance are experimentally investigated. The experimental analysis clarified that the generated shear stress of ERG under electric field is 20〜30 times as large as that of ERF. The ERG also shows the high repeatability of ER effect. These high performances of ERG suggest that the occurrence mechanism of ER effect in ERG is different from that in ERF, which originate the particle chain formation. The ER effect of ERG originates the change of frictional condition on ERG surface due to the variation of surface properties according to the applied electric field. Based on the performance analysis, ERG was applied to the clamp mechanism for aero-static slider. The zero force clamping mechanism was proposed by using the ERG. The error movement of slider in clamping does not occur and the clamping force is adjusted electrically.