title: Ionic Liquid-Assisted Electropolymerization for Lithographical Perfluorocarbon Deposition and Hydrophobic Patterning.
abstract: We developed a novel approach for hydrophobic patterning: combining the photolithography technique with ionic-liquid (IL)-based electropolymerization to fabricate a hydrophobic pattern. Perfluoro-functionalized 3,4-ethylenedioxythiophene (EDOT-F) dispersed in ILs was directly electropolymerized on substrates, which were patterned in advance with positive photoresists. The positive photoresists did not dissolve in ionic liquids during the electropolymerization process, and the poly(EDOT-F) film created hydrophobic domains, which resulted in hydrophobic patterning. This approach provides desired patterns with a lateral resolution consistent with the mask for photolithography. Two kinds of modified indium-tin-oxide-coated glass (ITO-glass) substrates were used to demonstrate the feasibility of process for creating a hydrophobic pattern: ITO-glass substrates coated with nanostructured PEDOT, and the same substrates coated with Au nanoparticles. By confining water droplets on these two patterned substrates to form droplet arrays, we demonstrated two potential applications: multiple droplet-type electrochemical cells and surface-enhanced Raman scattering platforms. In addition, we also applied this approach to create hydrophobic patterning on ITO-coated polyethylene terephthalate (ITO-PET) substrates. The droplet arrays remained well-organized on the ITO-PET substrates even when the substrates were bent. Our work successfully introduced ILs into the photolithography process, implying great potential for these green solvents.
authors: Department of Materials Science and Engineering, College of Engineering, National Taiwan University , No. 1, Sec. 4, Roosevelt Road, Taipei 10617, Taiwan.
authors: Jhih-Guang
authors: JG
authors: Wu
authors: Department of Materials Science and Engineering, National Cheng Kung University , 1 University Road, Tainan 70101, Taiwan.
authors: Cheng-Yang
authors: CY
authors: Lee
authors: Department of Materials Science and Engineering, National Cheng Kung University , 1 University Road, Tainan 70101, Taiwan.
authors: Shao-Shuo
authors: SS
authors: Wu
authors: Department of Materials Science and Engineering, College of Engineering, National Taiwan University , No. 1, Sec. 4, Roosevelt Road, Taipei 10617, Taiwan.
authors: Shyh-Chyang
authors: SC
authors: Luo
keywords: conducting polymers; electropolymerization; hydrophobic patterning; ionic liquids; lithography