A "thermal contour" movie reveals what happens to a microhotplate when it is heated and cooled. The National Institute of Standards Technology (NIST)-developed technology shows promise for a range of gas-sensing applications. For instance, the devices can be used in low-cost gas sensors that are used to detect freshness of food products or the leakage of chemicals.

The small size and fast heating speed of these micromachined devices made it difficult to measure dynamic temperature distribution, so NIST researchers use a new high speed transient thermal imaging system to make the movies.

The imaging system collects the temperature information every microsecond for each 0.006" square of space on the microhotplate. The system works by successively acquiring temperature response as a function of time at each coordinate of the device being tested and by using a coordinate-translation scheme to move between points. Thermal responses at different points are reconstructed to make the thermal contour movie.