介电微杆在圆极化电场中的可控电旋转行为

Controllable Electrical Rotation Behavior of Dielectric Micro-Rod in a Circularly Polarized Electric Field

为了解决悬浮在电解质溶液中的介电杆旋转方向难以改变的问题,并实现对介电杆的灵活控制,提出了单个介电微杆在外加旋转电场作用下旋转方向可以主动调节的方法。通过建立微流控芯片模型,在四相电极阵列中心布置或去除结构化的悬浮微电极,对电解质溶液中的介电微杆的运动开展研究。实验结果表明:在没有理想的可极化金属表面的情况下,测得的与行波电场相反的电旋转角速度总是远大于考虑非均匀表面传导的Maxwell-Wager界面极化理论所预测的角速度,最大角速度可达2.9(°)/s;在嵌入了偶极悬浮微电极的情况下,诱导出的双电层极化导致了一种新型的共场旋转模式,平均角速度从0.18(°)/s变化为-3.15(°)/s。提出的方法不仅实现了介电杆从反场到同场电动旋转行为的调节,而且大大加快了杆运动的角速度,为研究电旋转特性提供一定的参考。

To govern the rotation direction of the dielectric rod suspended in the electrolyte solution and realize flexible control of the dielectric rod,a method for adjusting the rotation direction of a single dielectric micro-rod under the action of external rotating electric field is proposed.By establishing a model of the microfluidic chip and arranging or removing the structured suspending microelectrode in the center of the four-phase electrode array,the rotating motions of the rigid dielectric micro-rod in electrolyte are researched.Experimental results show that without the polarizable metal surface,the measured angular velocity of anti-field electrorotation can reach 2.9(°)/s,more significant than that predicted by the Maxwell-Wager theory about the polarizable surface with consideration of uneven surface conduction.It is found that in the case of embedded dipole-suspended microelectrodes,the polarization of double electric layer leads to a new co-field rotation mode.This model changes the average angular velocity from 0.18(°)/s to-3.15(°)/s.The proposed method not only adjusts the electrorotation behavior of the dielectric rod from anti-field to co-field but also greatly speeds up the angular velocity,and it may provide a general reference for the design of the rotation characteristics.