MikrombolometerArrays

MikrombolometerArrays are infrared detector assemblies used to form thermal imaging systems. They are uncooled sensors that operate at ambient temperatures, relying on microfabricated bolometer elements that change resistance with temperature when they absorb infrared radiation.

Each pixel comprises a thin absorbing layer and a thermistor, often mounted on a micromachined support to minimize thermal conductance. The infrared radiation heats the sensing element, and the resultant resistance change is read by a CMOS readout integrated circuit, producing a video image. Arrays commonly use formats such as 160x120, 320x240, and 640x480, with frame rates ranging from tens to hundreds of hertz.

Materials used for the sensing element include vanadium oxide (VOx), amorphous silicon, or other metal-oxide compounds. The absorber is typically integrated with the thermistor on a MEMS microbridge or similar suspended structure to reduce thermal loss.

Spectral response is in the long-wave infrared region, approximately 8–14 micrometers. Performance is characterized by net temperature difference (NETD), responsivity, and noise equivalent temperature difference. Modern devices achieve NETD in the tens of millikelvin range under favorable conditions but still generally lag cooled detectors in sensitivity.

Applications include consumer and professional thermal imaging, building inspection, firefighting, automotive night vision, and industrial monitoring. Advantages include room-temperature operation, lower cost and power consumption, and compact form factors; limitations include lower sensitivity and drift requiring calibration, as well as fixed-pattern noise.