Uncooled microbolometers have become extremely popular as low cost thermal detectors used in FPAs for thermal imaging cameras. Most of the emphasis of researchers have gone towards the design and optimisation of device structures, materials, processes and readout electronics with this application in mind. However, microbolometers have the potential to be utilised towards the development of alternate applications. It is well known that the thermal conduction of microbolometers depend on the pressure surrounding the device, as this governs the dominating conduction method. This work investigates the possibility of employing a Ti thinfilm microbolometer as a low pressure sensor. A well known multi-physics simulation environment is utilised to simulate the microbolometer thermoelectric response over varied atmospheric pressure conditions. These simulation results are compared with a much simpler air pressure model than previous works using microbolometers, as well as experimental data, where the fabricated prototype showed a measured device TCR of about 0.085% K-1 and a sensitivity of about 0:701 – 10-9 W K-1 Pa-1.
J. Schoeman, J. Schoeman,
"Employing a microbolometer as a low pressure sensor", Proc. SPIE 9257, Sensors, MEMS and Electro-Optical Systems, 92570K (23 June 2014); doi: 10.1117/12.2066287; https://doi.org/10.1117/12.2066287