Development of Fluid Devices for Soft Machine by the Use of Electro-sensitive Fluids

在电场作用下从牛顿液体迅速转变为刚性固体的悬浮液被称为电流变流体。绝缘油在强电场作用下产生的二次流称为电流体动力效应。本研究的目的是建立液体马达、微泵等新型流体装置的设计方法，并将其应用于软机械。(1)开发了两种类型的ER流体。一是介孔二氧化硅（MPS）悬浮液，内电效应？通过将酞菁铜掺杂到二氧化硅表面的介孔中，大大改善了这一性能。另一种是聚合物混合颗粒的悬浮液。两种不具有内质网活性的聚合物的共混可以增强内质网效应。(2)当放置在梳状电极上的ER悬浮液通电时，从光滑的表面形成具有波形的精细图案。表面轮廓可以用单个正弦波或它们的叠加来近似。表面变形可以用电泳力和内电力的联合作用来表示。(3)将ER悬液夹在两个呈径向线状的圆盘电极之间。通电方式的改变引起了电极的运动。电极的平行运动可以主动调节，因此该技术在新型电流激电电动机中应用非常有吸引力。(4)众所周知，绝缘油在高电场中会产生EHD流，但我们成功地产生了水的EHD射流，并开发了新的喷墨装置。虽然油品的射流速度为几厘米/秒，但通过计算机模拟可以定量预测速度为1m/s的射流

The suspensions which undergo a rapid transition from Newtonian liquids to rigid solids on the application of electric fields, are referred to as electrorheological(ER) fluids. The secondary flow induced for insulating oils in high electric fields is called electrohydrodynamic (EHD) effects. The purpose of this study is the establishment of design method for new fluid devices such as liquid motor and micro pump, which can be applied to soft machines. (1) Two types of ER fluids are developed. One is the mesoporous silica(MPS) suspensions, the ER effect of? which is drastically improved by doping of copper phthalocyanine into mesopores of silica surfaces. The other is the suspensions of polymer blend particles. The ER effects can be enhanced by the blend of two polymers which are not ER-active. (2) When the ER suspensions which are placed on the comb pattern electrodes, are electrified, a fine pattern with a waveform is developed from the smooth surface. The surface profiles can be approximated by single sinusoidal waves or their superposition. The surface deformation can be expressed by a combination effect of electrophoretic and ER forces. (3) The ER suspensions were sandwiched between two flat disc electrodes with the radial line patterns. The change in electrification mode led to a motion of electrode. The parallel motion of electrodes can be actively regulated and therefore this technique is very attractive in application to new ER motors (4) It is well known that the EHD flow is induced for insulating oils in high electric fields, but we have succeeded in generating the EHD jet for water and developed the new ink jet devices. Although the velocity of EHD flow for oils is of the order of several cm/s, the EHD jet with a velocity of 1m/s can be quantitatively predicted by computer simulation