Abstract: The sensor may have a support structure having at least one substrate and at least one self-supporting membrane. At least one heating element has at least one electrical conducting track arranged on a first surface of the membrane. At least one thermopile, and the electrical conducting track of the heating element and/or the at least one heating element at least partly encloses the membrane on the first surface. An electronic evaluation and control unit is configured for detecting, on the basis of a calibration carried out by the heating element and a sample arranged at or on the membrane, at least one temperature gradient that has formed in the membrane owing to a thermodynamic process taking place in the sample and an associated release of heat or absorption of heat.

Abstract: This invention concerns a thermoelectric sensor of the air-backed type comprising a thin-film thermopile with a receiving area of approximately 1 mm.sup.2 under a protective atmosphere of atmospheric pressure. To increase the responsivity of such sensors the sensing junctions of at least 25 thermocouples whose legs have comparable coefficients of thermal conductivity are arranged in the receiving area with the legs having an average breadth-to-length ratio of at least 1:20.