Fabrication of porous carbon micropillars using a block copolymer as porogen

A technique to fabricate porous carbon micropillars using a block copolymer, F127, as porogen is described. In this process, negative tone photoresist (i.e. SU-8) mixed with F127 was photopatterned and carbonized under inert atmosphere. The thermal behavior of the photoresist precursor (F127 + SU-8) during carbonization process was characterized using differential scanning calorimetry and thermogravimetric analysis. Texture analysis on the carbon surface showed a mesoporous feature distribution. Electrochemical characterization based on the reaction of Fe(CN)(6)(3-)/Fe(CN)(6)(4-) redox couple was utilized to study the change in the effective surface area (A(eff)) of the porous carbon electrodes with different weight percentages of F127 in SU-8. These results indicated that porous carbon thin film electrodes derived from 10% F127 mixed in SU-8 had an A(eff) 185% compared to the conventional photoresist derived carbon electrode. This fabrication approach can be employed to produce reproducible high aspect ratio carbon microelectrodes with different shapes for various electrochemical devices. (C) 2010 Elsevier Ltd. All rights reserved.