Controlling Self-Assembly of Passive Colloids

3um silica microparticles monolayer (Image taken with Optical Microscope)

A good monolayer is needed to produce Janus particles efficiently with the expected activity. These monolayers can be created using wet methods , such as drop-casting or the Langmuir-Blodgett method, or dry methods, like manual rubbing . We focus on producing high-quality, consistent, and reproducible monolayers using dry-rubbing methods. We rub a PDMS stamp onto a pile of colloidal particles, resulting in long-range ordered monolayers onto the stamp . A good quality monolayer is achieved by controlling the rubbing pressure, rubbing speed, and direction of the stamp. We validate the optimized dry-rubbing method by creating monolayers using different substrates and particle stiffness. Following this, we are automating the protocol of monolayer formation for consistency, reproducibility, and large-scale assembly.