title: Single-step electropolymerization patterning of a polypyrrole nanowire by ultra-short pulses via an AFM cantilever.
abstract: Conducting polymers (CPs) have attracted a great deal of attention due to their unique properties; these properties are useful in implementing various functional devices, such as memory, and chemical and biological sensors. In particular, the nanopatterning of CPs is a key technology that will accelerate the adoption of CPs in fabricating nanoscaled multifunctional devices. This paper presents an innovative technique for forming polypyrrole nanowire (PPy-NW) patterns, without any additional pretreatment on the gold surface, using atomic force microscopy (AFM) and ultra-short pulse voltage. Applying the ultra-short pulse voltage to the AFM tip has the following advantage: since the electrochemical current is extremely localized around the tip, the successful formation of CP nanowires results. This is because the pulse width is much shorter than the resistor-capacitor (RC) time constant of the equivalent electrochemical circuit of our experimental set-up. This paper provides systematic results regarding the dimensional variation of the PPy-NW patterns produced by varying the electrical conditions of the ultra-short pulse, such as the pulse amplitude, width, and frequency. The results show that use of an ultra-short pulse is essential in fabricating PPy-NW patterns. Additionally, an ultra-short pulse offers excellent pattern controllability for both width (353 nm ∼ 3.37 µm) and height (2.0 ∼ 88.3 nm).
authors.affiliation: Department of Biomedical Engineering, Yonsei University, Wonju, Republic of Korea.
authors.forename: Kihwan
authors.initials: K
authors.lastname: Nam
authors.forename: Gyudo
authors.initials: G
authors.lastname: Lee
authors.forename: Huihun
authors.initials: H
authors.lastname: Jung
authors.forename: Jinsung
authors.initials: J
authors.lastname: Park
authors.forename: Chi Hyun
authors.initials: CH
authors.lastname: Kim
authors.forename: Jongbum
authors.initials: J
authors.lastname: Seo
authors.forename: Dae Sung
authors.initials: DS
authors.lastname: Yoon
authors.forename: Sang Woo
authors.initials: SW
authors.lastname: Lee
authors.forename: Taeyun
authors.initials: T
authors.lastname: Kwon
mesh_terms: D055664:Electrochemical Techniques / Q000379:methods*; D006046:Gold / Q000737:chemistry; D018625:Microscopy, Atomic Force / Q000379:methods*; D053770:Nanowires / Q000737:chemistry* / Q000648:ultrastructure; D058105:Polymerization; D011108:Polymers / Q000737:chemistry*; D011758:Pyrroles / Q000737:chemistry*
chemical_list: D011108:Polymers; D011758:Pyrroles; C067635:polypyrrole; D006046:Gold