Abstract: In many applications of nanotechnology, it becomes important to have a uniform size of nanoparticles in base fluids and on the substrate surfaces. The aim of this study is to sieve nanoparticles that are fabricated through either chemical or physical approach. In this study, a careful design of combinations of microchannels and microlakes can be used to separate nanoparticles that are either suspended or floating in the fluid flow in microchannels. The width of microchannel is around 1 mm. It is expected that smaller nanoparticles move faster than larger nanoparticles if microchannels can be designed properly. If possible, the nanoparticles with a uniform size can be collected in either microlakes or downstream exits. The microchannels and microlakes will be fabricated with photoresist. In addition, an AFM probe tip will be used to push the size walls of microchannels to control the channel width. In addition, the squeezing mechanism can push smaller nanoparticles to move ahead of larger nanoparticles suspended or floating in the fluid flow. An online optical system, UV-Vis spectrometer, will be installed to inspect the size of nanoparticles that flow through the measuring spot. After collecting the nanoparticles from the sieving process, TEM, ED, and EDX will be used to inspect the size, constitution, and crystal structure of the collected nanoparticles respectively. With an appropriate design of microchannels and microlakes, this study aims to sieve suspended or floating nanoparticles in a continuous flow through a squeezing mechanism on channel walls, a focused laser spot on nanoparticles, or an applied electrical field on the flow.