Surface-tension-dominant powerless nano/micro fluidic systems

This paper introduces three examples employing surface tension in micro/nano scale for fluid manipulation, precise dosage control, and powerless operation. Surface tension force, a line force, in micro scale is equally important as surface forces, such as friction or drag force. However, it becomes dominant in nanoscale when compared to surface or volume forces owing to scale effect. Therefore, the employment of surface tension would be effective and powerful in micro/nano fluidic systems. The first example is a fluidic network system employing surface tension for enzyme batch-immobilization and bio assay in parallel. The second system, a 3-in-1 micro/nano protein arrayer, utilizes passive surface tension force for protein array formation and protein assay processes. The third system, a powerless droplet manipulation system, employs surface hydrophobicity gradient for droplet manipulation. All three examples demonstrate efficient and precise fluid control results in micro/nano scale.