Dynamic photothermal-mechanical response of a microcantilever modified by carbon nanotube film.

Dynamic photothermal-mechanical response of a tri-material microcantilever illuminated by an intensity modulated laser source is theoretically analyzed using the heat dynamic differential model and finite element model based on the COMSOL 5.0. Tri-material microcantilever samples are fabricated by transferring carbon nanotube film onto a silicon microcantilever with aluminum coating. During the experiment, these samples are illuminated by an intensity-modulated laser pulse, and the maximum photothermal response frequency is ∼173  Hz. Experimental results are consistent with theoretical analyses. The photothermal spectroscopy detection of water vapor in the open environment is carried out, and the linear correlation coefficient between spectroscopy signal and water concentration is 0.997. Experimental results demonstrated the feasibility of tri-material microcantilever as a thermal sensor for photothermal deflection spectroscopy.