Theory of Infrared Detector Based on the Microcantilever Resonant Frequency Temperature Dependence

We developed a theory for the infrared (IR) thermal detector whose function is based on the dependence of the microcantilever resonant frequency on the thermal stress caused by IR radiation. We study performance of such a sensor using the general theory of microcantilever based resonators. The stress in the microcantilever is a result of the combined effect of the room temperature built-in stress stemming from the fabrication process and the thermal stress caused by the beam heating. We derive for the first time the analytical expressions for basic parameters, sensitivity, noise and detectivity, of such a sensor.