200 Fabrication of Micro and Nano Pillar Arrays by Dielectrophoresis Force Driven Reverse-Imprint

In this study, micro/nano poly-pillar arrays are fabricated by dielecphoretic-force-driven-filling reverse-imprint method. In this method, a conducive mold is dipped into a pool of pre-polymer, which is dropped onto a conductive substrate, and a voltage is applied between the mold and the substrate. The liquid-dielectrophoresis (L-DEP) force can be generated by the applied voltage to drive pre-polymer filling into cavities of the mold. After the filling process is completed, the mold with pre-polymer in its cavities is moved out off the pre-polymer pool and put onto a target substrate. Then the pre-polymer is cured the by UV-light irradiation and subsequently the mold is removed from the target substrate to obtain the poly-pillar arrays on the target. Using this technique, micro/nano poly-pillar arrays with high aspect ratio (more than 10:1) are duplicated. This patterning method can overcome the drawbacks of the mechanically induced mold deformation and position shift in conventional imprinting lithography.