Wall-less microfluidic channels using 3-dimemsional ring arrays

This paper presents a method to construct microfluidic channels without physical walls - wall-less microchannels. In order to minimize liquid surface areas contacted to solid walls, tliis method uses three dimensional ring arrays compared to the previous wall-less microfluidics based 011 two dimensional patterns of hydrophilic and hydrophobic areas. Thus, we can form free-standing liquid pathways surrounded by an immiscible liquid between distant rings in the ring arrays, hi the experimental study, we reduced the liquid-solid interface areas per unit volume to 17.3% of that of the conventional microchannels with square cross-sections. We expect that this aspect would be important in micro/nano-fluidics. whose surface -area-to-volume ratio is extremely large.