Abstract: In an embodiment a method includes forming a dielectric membrane on a semiconductor substrate comprising a bulk-etched cavity portion, forming a heater within or over the dielectric membrane, forming a material for sensing a gas on a side of the dielectric membrane, forming a support structure near the material, wherein the support structure comprises an inorganic material and forming a gas permeable region coupled to the support structure in order to protect the material.

Abstract: A gas sensor with a gas permeable region is disclosed. In an embodiment a gas sensor includes a dielectric membrane formed on a semiconductor substrate having a cavity portion, a heater located within or over the dielectric membrane, a material for sensing a gas, wherein the material is located on one side of the dielectric membrane, a support structure located near the material, a gas permeable membrane coupled to the support structure so as to protect the material, wherein the semiconductor substrate forms the support structure.

Abstract: We disclose herein a method for heating a gas sensing material formulation on a microhotplate which comprises: a dielectric membrane formed on a semiconductor substrate comprising an etched portion; and the gas sensing material formulation being located on one side of the dielectric membrane. The method comprising: selectively heating the gas sensing material formulation using an infra-red (IR) heater located over the substrate, and controllably cooling the semiconductor substrate using a cooling baseplate provided under the substrate and using an insulating medium located between the substrate and the cooling base plate so that a gas sensing structure is formed on said one side of the dielectric membrane from the gas sensing material formulation.

Abstract: We disclose herein a method for testing a batch of environmental sensors to determine the fitness for purpose of the batch of environmental sensors, the method comprising: performing a plurality of electrical test sequences to the sensor inputs of the batch of environmental sensors to measure electrical responses of the sensor outputs of the batch of environmental sensors; correlating the measured electrical responses from the batch of environmental sensors to predetermined environmental parametric ranges of at least one environmental sensor so as to define correlated electrical test limits; and determining the fitness for purpose of the batch of environmental sensors if the measured electrical responses are within the correlated electrical test limits.

Abstract: We disclose herein a method for heating a gas sensing material formulation on a microhotplate which comprises: a dielectric membrane formed on a semiconductor substrate comprising an etched portion; and the gas sensing material formulation being located on one side of the dielectric membrane. The method comprising: selectively heating the gas sensing material formulation using an infra-red (IR) heater located over the substrate, and controllably cooling the semiconductor substrate using a cooling baseplate provided under the substrate and using an insulating medium located between the substrate and the cooling base plate so that a gas sensing structure is formed on said one side of the dielectric membrane from the gas sensing material formulation.

Abstract: Disclosed herein is a gas sensing device comprising a dielectric membrane formed on a semiconductor substrate comprising a bulk-etched cavity portion, a heater located within or over the dielectric membrane, a material for sensing a gas which is located on one side of the membrane, a support structure located near the material, and a gas permeable region coupled to the support structure so as to protect the material.

Abstract: We disclose herein a method for testing a batch of environmental sensors to determine the fitness for purpose of the batch of environmental sensors, the method comprising: performing a plurality of electrical test sequences to the sensor inputs of the batch of environmental sensors to measure electrical responses of the sensor outputs of the batch of environmental sensors; correlating the measured electrical responses from the batch of environmental sensors to predetermined environmental parametric ranges of at least one environmental sensor so as to define correlated electrical test limits; and determining the fitness for purpose of the batch of environmental sensors if the measured electrical responses are within the correlated electrical test limits.