Patent ID: 7338640

Claim:
A calorimetric gas sensor, comprising: a reference cell; a sensor cell comprising an adsorbent layer configured to adsorb a defined amount of gas and to desorb a portion of the defined amount of gas when heated, wherein the sensor cell and the reference cell are fabricated on a sensor substrate; a thermopile sensor disposed on the sensor cell and the reference cell and configured to measure heat flux between the sensor cell and the reference cell, wherein the thermopile sensor comprises: a sacrificial layer disposed on a substrate; a low-thermal-conductivity layer disposed on the sacrificial layer; a first set of conductive arms and a second set of conductive arms disposed on the low-thermal-conductivity layer to form a plurality of thermal junctions, wherein the plurality of thermal junctions is adapted to form a plurality of hot junctions and a plurality of cold junctions when subjected to a difference in temperature, and wherein the sacrificial layer and the low-thermal-conductivity layer include a cavity etched therebetween.