In recent years the engineering of organic bioelectronics to create electronic interfaces with cells or living tissue has gained much attention. In this field the conjugated polymer Poly(3,4-ethylenedioxythiophene) doped with Poly(styrenesulfonate) (PEDOT:PSS) has become the most used material because of its biocompatibility, electrical conductivity, chemical stability and easy processability. PEDOT:PSS has been extensively utilized in planar thin-film devices for electrophysiological recordings, drug delivery and electric stimulation. 
A newly emerging trend is the use of 3D PEDOT:PSS networks for applications like tissue engineering or cell culture monitoring.  Tetrapodal ZnO networks have proven to be a versatile toolkit for the fabrication of new 3D micro- and nanomaterials because of their tunable pore size, density and ease of fabrication.  This work presents a novel approach to create 3D open-porous networks of PEDOT:PSS using sacrificial ZnO networks as template materials.
For the fabrication, the ZnO networks were infiltrated with aqueous dispersions of PEDOT:PSS. In order to enhance the mechanical stability a low temperature, a cross-linking step using ionic species was introduced. The final material is easily obtained after etch-removal of the sacrificial ZnO. This process offers advantages compared to previous approaches due to the truly open porous geometry and easily tunable dimensions. The electrical and mechanical properties of the obtained networks as a function of the total concentration of PEDOT:PSS, the degree of crosslinking and treatment with different acids will be discussed.
 Inal, S., Rivnay, J., Suiu, A.-O., Malliaras, G.G., McCulloch, I. Conjugated Polymers in Bioelectronics. Acc. Chem. Res. 51, 1368-1376, 2018
 Pennachio, F.A., Garma, L.D., Matino, L., Santoro, F. Bioelectronics goes 3D: new trends in cell-chip interface engineering. J. Mat. Chem. B 6, 7096-7101, 2018
 Mishra, Y.K., Adelung, R. ZnO tetrapod materials for functional applications. Materials Today 21, 6 (631-651), 2018