title: Janus Si micropillar arrays with thermal-responsive anisotropic wettability for manipulation of microfluid motions.
abstract: In this paper, Janus micropillar array (MPA) with fore-aft controllable wettability difference was demonstrated. With two-step modification process, we successfully decorate the Janus pillar skeletons with wettability-switchable polymer brush on one side and hydrophilic self-assembled monolayer on the other. Owing to the switchable wettability of the polymer brush, the patterned surface could switch between anisotropic wetting and isotropic wetting at different temperatures, which gives the possibility of coupling the well-designed surface with microfluidic channel to manipulate the microfluid motion. Additionally, a further photothermal control of microfluid was also established based on the thermal-responsive Janus MPA through introducing infrared light to adjust the temperature of the microfluidic system. We believe that the thermal-responsive Janus micropillar arrays would provide a new strategy to control the flow and motion of fluids in microfluidic channels and show potential applications in the future microfluidic chips.
authors.affiliation: State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University , Changchun, 130012, P. R. China.
authors.forename: Tieqiang
authors.initials: T
authors.lastname: Wang
authors.forename: Hongxu
authors.initials: H
authors.lastname: Chen
authors.forename: Kun
authors.initials: K
authors.lastname: Liu
authors.forename: Shuli
authors.initials: S
authors.lastname: Wang
authors.forename: Peihong
authors.initials: P
authors.lastname: Xue
authors.forename: Ye
authors.initials: Y
authors.lastname: Yu
authors.forename: Peng
authors.initials: P
authors.lastname: Ge
authors.forename: Junhu
authors.initials: J
authors.lastname: Zhang
authors.forename: Bai
authors.initials: B
authors.lastname: Yang
keywords: Janus pillar array; anisotropic wetting; smart microfluidic manipulation; thermoresponsive