Multi-parametric sensor with bridge structure

A method for operating a sensor for detecting and/or analysing a gas, the sensor comprising

• a substrate (1);
• a recess or opening (2) arranged in the substrate (1);
• a first bridge structure (3 a) and a second bridge structure (3 b), extending over said recess or opening (2) and being anchored in the substrate (I);
• wherein
• the first bridge structure (3 a) forms a first hotplate (6a) and comprises
• a first patch (8a) of sensing material, in particular of a metal oxide material, arranged on the first hotplate (6a);
• electrodes (30, 31) adapted to measure an electrical property of the first patch;
• a heater (20) adapted to heat the first hotplate (6a);
• the second bridge structure (3b) comprises at least a temperature sensor (34);
• and
• the sensor comprises circuitry for driving the heater and for processing signals from the electrodes and the temperature sensor;
• the method comprising
• performing, in a first operation mode of the sensor, a measurement of an electrical property of the first patch (Ba);
• and
• operating, in a second operation mode of the sensor, the second bridge structure (3b) in a sensing mode to perform a measurement of a thermal property of the gas, wherein the thermal property is a thermal capacity and/or a thermal conductivity and/or a thermal diffusivity of the gas.