###### Abstract
A subsequent article from the same group [53] presented detailed results and a discussion of the fluid pumping and flow-behavior control with semiconductor diodes subjected to external AC electric fields. The diodes were fixed alongside the insulating channel walls and, depending on their mutual orientation, could work as pumps or mixers. The parameters that regulated the fluid flow were identified, and their effects were studied numerically. Although the present work and the relevant study by [PERSON] et al. used an anisotropic solid object to actuate biased electrohydrodynamic fluid motion, the underlying physical mechanism was completely different. Our proposed idea of the Janus AC-FFET is based upon time-averaged nonlinear induced-charge electro-osmosis at polarizable metal/electrolyte interfaces with symmetric breaking in the flow profile along two orthogonal directions, with the potential to achieve the simultaneous pumping and mixing of analytes in microfluidic channels, while remotely powered microfluidic devices embedding miniature diodes are intrinsically created by linear electro-osmosis acting on a native electrical double layer under a local DC voltage rectified from the globally applied AC electric field [52; 53]. More importantly, the research group led by [PERSON] has made a series of breakthrough scientific achievements in the field of electrokinetic microfluidics in the past two decades [54; 55; 56; 57; 58; 59; 60; 61]. The standard model of ICEO was proposed by [PERSON] and [PERSON] in a pioneering study [62]. In the mathematical derivation of the standard model, the polarizable solid surface in contact with the electrolyte solution is assumed to be a perfect metal conductor of an equal body potential when subjected to a background DC or low-frequency AC electric field. Thus, it may be difficult for the standard model to describe the phenomenon of ICEK adjacent to non-metallic solid objects. To investigate the Janus AC-FFET in detail, under the approximation of a thin IDL and a small IZP, starting from the leaky dielectric theory, we derived a rigorous macroscopic mathematical model that can capture inhomogeneous electrochemical polarization and time-averaged ICEO slipping at the pillar/electrolyte interfaces on both the metal- and dielectric-phase surface of the Janus post. Considering the high impedance of the dielectric phase, the capacitive charging of IDL on its insulating surface is usually at least two orders of magnitude weaker than that on the conducting surface, so it can be safely disregarded in most situations [63]. However, in the transition region between the metal and the dielectric phase, there is appreciable ICEO slipping velocity, which is identical to the strong ICEO jet observed around sharp dielectric corners [64, 65]. That is, the standard model of ICEK may malfunction when a dielectric solid phase with sharp boundaries is involved in microfluidic channels. In this sense, by resolving the phenomenon of ICEO streaming on solid surfaces with electrical polarizability, our physical description of the ICEO is more accurate than the standard model obtained by the linear RC circuit theory on perfect conductors. It is worth noting that the standard model is generally correct when mere metal conductors are utilized to actuate ICEO convection under the Debye-Huckel limit. Armed with this utilitarian calculation model, it is possible to explore the basic physics underlying the Janus AC-FFET. Specifically, AC field-effect flow control through the metal-phase gate voltage of Janus pillars immersed in an electrolyte solution allows Janus AC-FFET to generate arbitrary symmetry breaking in the lateral flow pattern of ICEO whirlpools to produce a net transversal rotating motion \(u_{y}\), which already possesses a horizontal unidirectional pump motion \(u_{x}\), caused by inhomogeneous material composition.