Integrated gas sensor device, in particular for detecting carbon monoxide (co)

A process comprising:

• manufacturing an integrated gas sensor device including:
• forming an insulating layer on a first surface of a substrate;
• forming a working electrode, a counter electrode, and a reference electrode on the insulating layer;
• forming one or more first through holes in the substrate;
• forming second and third through holes in the insulating layer, the working electrode and the counter electrode having active areas, respectively, that are exposed to an external environment by the plurality of second through holes and the plurality of third through holes, respectively, and the one or more first through holes in the substrate;
• forming an electrolyte layer on the working electrode, the counter electrode and the reference electrode;
• and
• forming a hydrogel layer on the electrolyte layer, the electrolyte and hydrogel layers covering at least the working, counter, and reference electrodes, the electrolyte and hydrogel layers having a footprint perimeter on the insulating layer that is substantially the same, the hydrogel layer being operable to store water.

A method, comprising:

• forming a first insulating layer on a first side of a substrate, the substrate having a second side opposite the first side;
• forming a patterned layer on the first insulating layer, the patterned layer having a first electrode, a second electrode, and a third electrode;
• and
• forming a electrolytic hydrogel layer on the patterned layer, portions of the electrolytic hydrogel layer between each of the first, second, and third electrodes, respectively, and portions of the electrolytic hydrogel layer in the first electrode, the second electrode, and the substrate at the first side.