Abstract: We disclose herein a method of annealing a composition to produce a film for a sensing device, the composition comprising at least one metal oxide material, the method comprising: depositing the composition on one side of a substrate; providing a source of electromagnetic radiation in a proximity to the composition; exposing a surface of the composition to a first dose of electromagnetic radiation, wherein the first dose comprises a first property which induces annealing of the composition; exposing the surface of the composition to a second dose of electromagnetic radiation, wherein the second dose comprises a second property which induces annealing of the composition, wherein the first property is substantially the same or different to the second property.

Abstract: We disclose herein a gas sensor comprising a catalyst material; a temperature detector configured to measure a change in temperature of the catalyst material; and a plurality of electrodes configured to measure the current and/or resistance of the catalytic material. The gas sensor can be formed using CMOS or CMOS-SOI technologies.