Highly Sensitive Low Power Metal Oxide Sensors on Nanoporous Anodic Alumina Substrates

The high physical, chemical, and mechanical properties of anodic alumina open up broad prospects for its use as a passive substrate for gas sensors. The results of practical tests of low-power thin-film gas microsensors manufactured on nanoporous anodic alumina substrates are presented. Due to the original design and the nanostructured gas-sensitive layers (GSLs), the sensors had low power consumption and a high sensitivity to 10 ppm H2 and 10 ppm CO. Comparative studies of gas sensor responses were carried out with three GSLs of In2O3–Ga2O3; SnO2–Pd and In2O3–SnO2 at different operating temperatures. All sensors demonstrated high performance; in particular, the energy consumption during measurements did not exceed 30–40 mW, the maximum sensitivity for CO reached 350%, and for H2 up to 140%, the response time was no more than 10–15 s, and the regeneration time—no longer than 20–25 s, high measurement reproducibility and operation stability, the drift of GSLs was 3%–5% over several months. With proper organization of production, such sensors are capable of competing with many advanced analogs.