Free accessible microchannel formed by wide range wettability control using nano-geometric surface

We succeeded in manipulating a microparticle in a free accessible microchannel formed by air-liquid interface by using the on-chip robot. To pattern the stable air-liquid interface in the microfluidic chip, we controlled the wettability of the surface using the nano-geometric surface, which was fabricated by the hybrid mask lithography technique using composite of photoresist and nanoparticle. By adjusting the density of nanopillar coated fluorocarbon or SiO₂, the contact angle was controlled from 0 degree to 160 degree. Finally, we demonstrated the on-chip transfer and isolation of the microparticle by the developed free accessible microchannel and the MMT.