Lift-off patterning of multi-walled carbon nanotube and PEDOT:PSS composite films with fluorinated polymer templates

This paper reports a micro patterning method for multi-walled carbon nanotubes (MWCNTs), whose patterns were defined by a poly(1H,1H,2H,2H-perfluorodecyl methacrylate) (PFDMA) mask in a lift-off process. The PFDMA layer on the patterned polydimethylsiloxane (PDMS) mold was transferred to a polyethylene naphthalate (PEN) film using a Micro-Contact Printing (μCP) technique. In contrast to conventional photoresist masks, the PFDMA polymer template was not damaged by the solvent used for the MWCNT dispersion, isopropyl alcohol (IPA), which enabled the precise and clean deposition of MWCNTs. Moreover, a hydrofluoroether solvent, which was used to remove the PFDMA template, did not show any signal for chemical interactions with the PEN substrate or poly(3,4-ethylene dioxythiophene):poly(styrene sulfonate) (PEDOT:PSS). This orthogonal character led to the successful lift-off patterning of MWCNTs/PEDOT:PSS composite films. The micro-patterned composite films could be examined further as a thin film heater with a bending radius of 15 mm, generating enough heat to reach a maximum temperature of 53 °C with an applied voltage of 30 V.