Performance analysis of microcantilever arrays for optical readout uncooled infrared imaging

The thermal imaging performance of bi-material microcantilever uncooled infrared focal plane array depends on its thermal deformation sensitivity (the ratio of the microcantilever deformation to a temperature change of thermal objects). In this paper, two microcantilever arrays with different structures are designed and fabricated, which contain multi-fold interval metallized legs. The thermo-inducing incline angle of the microcantilever is measured by knife-edge filtering optical readout method. One of the structures has deformation magnification effect, which can magnify the incline angle of microcantilevers under the same temperature rise. The other structure aims at keeping microcantilevers from the influence of environmental temperature fluctuation. The performance of the microcantilever structures is modeled. Thermal images of human body are obtained with the fabricated microcantilever arrays. The thermal deformation sensitivities of two structures are measured, which agree with the modeling analyses.