A pixel-by-pixel thermal conductance tuning mechanism for uncooled microbolometers

Abstract

The increase in the demand of using infrared detectors for thermal imaging of high temperature scenes initiated the research in microbolometer arrays with high operation temperature range. An efficient way of increasing this range is tuning the thermal conductance of the microbolometer array by electrostatic actuation, which is achieved by applying an actuation voltage to the substrate. However, using the substrate for actuation does not support pixel-by-pixel actuation, limiting the capabilities of the tunability. In this research, we demonstrate applying the actuation voltage to the micromirror which is located below the microbolometer. To avoid contact of the microbolometer to the micromirror, stoppers are used. We report that the thermal conductance is doubled at an actuation voltage of 12 volts, making it an efficient mechanism that can be used at next generation adaptive microbolometers.