Omni-Liquid Droplet and Bubble Manipulation Platform Using Functional Organogel Blocks

Droplet and bubble manipulation in air and underwater, respectively, are of interest because of their potential applications in various areas related to microfluidics, gas collection, and other industrial applications. However, the fabrication of manipulation platforms capable of performing various functions (merging and mixing) and directionally moving droplets/bubbles on a single platform has rarely been reported. This paper describes a multifunctional manipulation platform designed using a slippery organogel channel capable of manipulating droplets and bubbles. The manipulation block can be fabricated by forming a polydimethylsiloxane channel using a 3D-printed mold generated by a commercial 3D printer and filling it with a slippery organogel precursor. The fabricated manipulation platform can move various droplets regardless of viscosity, surface tension, acidity, or basicity; has a merging function; and can enhance mixing. As a functional block application, polyvinyl alcohol-boric acid hydrogel is synthesized on a slippery organogel channel. Moreover, because of the nature of block assembly, new manipulation platforms that can perform desired functions can be created by assembling blocks. The proposed functional manipulation platform overcomes existing limitations and would have practical applications.