Gas Sensors Fabricated from Ceramic Suspensions by Micromolding in Capillaries

Micromolding in capillaries has been used to fabricate an array of SnO2 gas sensors (see Figure) using colloidal suspensions. The micromolding procedure was integrated in a sequence of conventional photolithography steps. Miniaturized gas sensors on sapphire single crystal substrates showed responses of 100 ppm for H2 and 600 ppm for CO, the active sensing area being only 10 by 40 μm2.