The pyrolyzed carbon structures were contacted with silver conducting paste (Ferro GmbH ® ) on the contact pads. Furthermore, a defined area of 11 × 10 mm area for IDS1 and 10 × 6 mm for IDS2 around the electrodes was encapsulated by PDMS (Sylgard 184 elastomer kit; Dow Chemicals ® ) to define a specific reservoir for the electrolyte. As electrolyte confinement a 3Dprinted polypropylene reservoir was deposited on top of the structure and sealed with PDMS.