Conducting polymer microelectrodes anchored to hydrogel films

We report the fabrication of totally organic hydrogelbased microelectrodes of poly(3,4-ethylenedioxythiophene) (PEDOT), which exhibit a lowered sheet resistivity of about 100 Ω/□. The preparation process starts with the electrodeposition of conductive PEDOT (ca. 20 S cm^-1) on Pt microelectrodes. After laminating hydrogels onto the PEDOT-modified Pt electrode substrates, a second PEDOT (low conductivity) layer was electrodeposited to anchor the first PEDOT film to the hydrogel. Finally, the hydrogel sheet with PEDOT micropatterns was peeled off by taking advantage of the electroactuation property of PEDOT. The process proved to be versatile, allowing the use of most natural and synthetic hydrogels including agarose, collagen, polyacrylamide, and so on.