Abstract
In this paper, we present air-liquid interface microchannel to obtain the robustness of flow condition of microchannel from fluctuation of microtool. To obtain the air-liquid interface in microfluidic chip, we propose the hybrid mask lithography to fabricate nanopillar which has the function to control the contact angle of the surface and the micro-pattern in wafer-level large area simultaneously. The technique utilized the hybrid mask of photo mask and nanoparticle mask to obtain the simple fabrication of nanopillar with micro-pattern in wafer-level large area simultaneously. We have succeeded in controlling of the density of nanopillar between 1.6×10^<-2> to 5.9×10^<-1> pillars/μm^2 as a function of the weight ratio of nanoparticle. We have applied the density control to control contact angle between about 0 and 36 degrees by nanopillar with SiO_2 film, and between about 113 and 160 degrees by nanopillar with fluorocarbon film. Finally, we have succeeded in fabrication of air-liquid interface microchannel by surface geometric control. Furthermore, we have succeeded in transporting 20 μm microbeads at the max speed of 2.1 mm/s and inserting micro-probe into microchannel stably.
