Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)The fabrication of three-dimensional (3D) polypyrrole conductive tracks through the porous structure of paper is demonstrated by the first time. We combined paper microfluidics and gas-phase pyrrole monomers to chemically synthesize polypyrrole-conducting channels embedded in-between the cellulose fibers. By using this method, foldable conductive structures can be created across the whole paper structure, allowing the electrical connection between both sides of the substrate. As a proof of concept, top-channel-top (TCT) and top-channel bottom (TCB) conductive interconnections as well as all-organic paper-based touch buttons are, demonstrated.8 1066110664CNPq [483550/2013-2]FAPESP [2013/22127-2]Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)