Electrochemical fountain pen nanofabrication of vertically grown platinum nanowires

Abstract

Local electrochemical deposition of freestanding platinum nanowires was demonstratedwith a new approach—electrochemical fountain pen nanofabrication (ec-FPN). The ec-FPNexploits the meniscus formed between an electrolyte-filled nanopipette (‘the fountainpen’) and a conductive substrate to serve as a confined electrochemical cell forreducing and depositing metal ions. Freestanding Pt nanowires were continuouslygrown off the substrate by moving the nanopipette away from the substrate whilemaintaining a stable meniscus between the nanopipette and the nanowire growth front.High quality and high aspect-ratio polycrystalline Pt nanowires with diameter of∼150 nm andlength over 30 µm were locally grown with ec-FPN. The ec-FPN technique is shown to be an efficient andclean technique for localized fabrication of a variety of vertically grown metalnanowires and can potentially be used for fabricating freeform 3D nanostructures.