Thin-film temperature sensor made from polymer-derived ceramics based on laser pyrolysis

Polymer-derived ceramics (PDCs) are ideally suited to the manufacture of thin-film sensors due to their low cost, ease of moulding and resistance to high temperatures and oxidation. Conventional heat treatment of single-layer PDC films is typically carried out in a tube furnace and takes at least 15 h. In this paper, laser pyrolysis was used to fabricate a sensitive thin film of a PDC thin-film temperature sensor. The pyrolysis process took only 1.7 s. The resistance of the sensing head was tested for three temperature cycles from room temperature to 800 degrees C using a protective PDC film overlaid on the sensitive film. The resistance-temperature test results show good repeat-ability of the PDC sensor head. The results of the temperature test experiments show that this laser pyrolysis based temperature sensor is capable of measuring temperature from room temperature to 800 degrees C. This provides a rapid method for the fabrication of PDC film heat flux sensors, and hot wire/film anemometers, etc.