## Materials and Methods  
### Basic Device Geometry of Microfluidic Pump and Mixer Utilizing Janus AC-FFET  
On the basis of Janus AC-FFET, we carried out a comprehensive simulation analysis of the flow pattern of ICEO near an individual metal-dielectric Janus microcylinder, as well as of the performance of a highly integrated micropump and mixer arranging an array of discrete Janus pillars (Figure 1). The basic structure of a typical ICEO microfluidic device with circular Janus posts, which has dual functionality in simultaneous electro-convective pumping and mixing of incoming chemical analyte, is schematically shown in Figure 1A. The active microdevice has three branch channels, including two liquid inlets and one liquid outlet for sample discharge, which each have direct connection with three reservoirs (not shown). The entrance of the straight main channel of length L\({}_{C}\) and width W\({}_{C}\) has a Y-shaped geometry (Figure 1A). A pair of 3D Ag-PDMS conducting plates are embedded into both sidewalls of the main-channel of height H\({}_{C}\), serving as the driving electrodes (DE) powered by an AC voltage supply. Moreover, a series of metal-dielectric Janus microcylinders of radius R and a neutral metal phase angle \(\alpha=180^{\circ}\) with sequentially reversed gate-voltage polarity are disposed along the centerline of channel bottom surface parallel to the sidewall DE (Figure 1B). The polar interface bisecting the two distinct hemispheres of each Janus pillar is perpendicular to channel sidewalls, with an azimuth angle \(\theta=90^{\circ}\) relative to the horizontal x-axis (Figure 1B). In the numerical simulation, the fluid channel is filled with aqueous electrolyte of electric conductivity \(\sigma_{\text{f}}=0.001\) S\(\cdot\)m\({}^{-1}\) and permittivity \(\varepsilon=80\varepsilon_{0}\). The left upstream inlet releases fresh liquid solution of same electrical properties, which contains the target fluorescein nanoparticles for simultaneous electrokinetic transport and stirring driven by ICEO convection, while the right entrance merely provides pure electrolyte solution without any analytes. No external moving parts or syringe pumps are needed to achieve effective fluid mixing in the microdevice applying Janus AC-FFT due to net pump-flow component of ICEO eddies induced naturally around non-uniformly polarized solid surfaces, such as Janus micropillars used herein (Figure 1C). Once we turn on the multichannel sinewave generator, it imposes a time-harmonic driving voltage of V\({}_{\text{D}}\)cos(2\(\pi\)ft) to the pair of 3D DE plates on both channel sidewalls, and an in-phase AC gate signal of either V\({}_{\text{G1}}\)cos(2\(\pi\)ft) or V\({}_{\text{G2}}\)cos(2\(\pi\)ft) of same oscillating frequency but distinct gate-voltage amplitude to the metal phase of the array of discrete Janus micropillars. Here, V\({}_{\text{D}}\) is the amplitude of AC-driven voltage, and V\({}_{\text{G1}}\) and V\({}_{\text{G2}}\) are those of AC gate voltage applied to the odd and even sequence of the repeating Janus posts when observing from upstream to downstream, respectively (Figure 1A). The f and \(\omega=2\pi\)f are the linear and angular field frequencies, respectively, of the applied voltage. In most situations, V\({}_{\text{G1}}\) and V\({}_{\text{G2}}\) have opposite polarity for adjacent pillars. The specific bias degrees of gate voltage \(\beta_{\text{odd}}=(V_{\text{G1}}-0.5V_{\text{D}})/0.5V_{\text{D}}\) and \(\beta_{\text{even}}=(V_{\text{G2}}-0.5V_{\text{D}})/0.5V_{\text{D}}\) are equal in magnitude but opposite in sign with \(\beta_{\text{odd}}=-\beta_{\text{even}}\) for odd- and even-numbered Janus micropillars in the discrete arrangement.