Facile Nanopatterning of PEDOT:PSS Thin Films

Nanopatterned conducting polymer poly(3,4-ethylenedioxythiophene) poly(styrene sulfonate) (PEDOT:PSS) films are obtained using a new, facile fabrication method. In this method, an epoxy supporting layer is used to facilitate the transfer of nanopatterns from a polydimethylsiloxane mold to rigid or flexible substrates. This process overcomes several limitations that are previously introduced when using other nanopatterning techniques such as nanoimprint lithography and capillary force lithography. Two sets of nanopatterned PEDOT:PSS/Gold (Au) electrodes are fabricated with different dimensions: set 1 with 87 nm linewidth, 140 nm pitch, 30 nm depth; and set 2 with 157 nm linewidth, 280 nm pitch, 26 nm depth, respectively. The electrochemical impedance of these electrodes is measured to be lower than that of flat electrodes fabricated following the same process. These findings open the way for fabricating smaller electrodes with reduced impedance. Possible applications can be in the field of biosensing, neural recordings, and interfaces, where decreasing the contact impedance plays a key role.