Our group developed a new generation of chip-based small-scale devices for continuous purification of chemicals and nanoparticles, based on the interactions of analyte with multiple types of driving forces in an electro-fluid-dynamic (EFD) system. One series of the purification devices has the electric field in parallel with the fluid flow direction (E?F), while the other series has two orthogonal driving force fields (E?F). Our two-dimensional (2D) EFD devices, in which both electric field and pressure-driven flow field are simultaneously utilized in 2D channel networks, provide better control on the analyte molecules or nanoparticles by having more adjustable variables. More importantly, continuous purification can be achieved with these devices. Our initial work based on simulations and polymer particles have shown the feasibility of the 2D EFD devices, and some results have been published. TO BE CONT'D