Microfluidic patterning of nanoparticle monolayer: Mechanism analysis and noncontinuously patterning approach

Presently, with the development of nanofabrications, patterning nanoparticles into monolayer attracts tremendous interests. In this work, a microfluidic-assisted nanoparticle monolayer patterning approach was proposed to produce noncontinuous patterns based on the well-known continuity equation in fluid mechanics. Soft-lithography used in this approach greatly reduced the cost and time of the fabrication process. In addition, nanoparticles sedimentation and washing are found to be two important processes to obtain high quality nanoparticle monolayer patterns, and by tuning technique parameters, such as channel size, flow rate, working time, etc., mechanism of the novel microfluidic patterning technique was studied to interpret the whole patterning process and guide the patterning microchannel design. Noncontinuous nanoparticle monolayer patterns were realized simultaneously by varying the width within a single microchannel, which further widened the applicability of this technique in the nanofabrications.