Design and modeling of thermally excited microcantilever sensors for airborne nanoparticles mass detection

In this paper, the designs and simulations of novel silicon in-plane and out-of-plane thermally excited microcantilevers for detecting airborne nanoparticles (NPs) mass are reported. The electrothermal microcantilever consists of heating resistors, sensing piezoresistors NPs sampling electrode. By means of FEM (finite element modeling), the geometric structure is analyzed by investigating the resonant modes of the cantilevers upon electrothermal actuation. The simulation shows the in-plane mode design results in lower driving power than that of out-of-plane mode design. NPs sampling is dementstrated experimentally to validate the sensing method. The current fabricated sensor exhibits mass sensitivity of 5.4 Hz/ng with the quality factor of 1000.