Mass-loading effect on quality factor of floppy silicon microcantilever in free air space

The floppy microcantilever usually exhibits a low quality factor in free air space, because of air damping. Here, the authors present an approach to enhance the quality factor through adding a mass at the free end of the microcantilever. The mass loading effect is theoretically investigated and experimentally validated. Based on the theory, the quality factor of the mass-loaded microcantilever is proportional to (m_can+m)^1/2, where m_can is the effective mass of the microcantilever and Δm is the added concentrated mass. In the experiments, the silicone grease is added as the mass on a 465 × 10 × 0.85 × μm³ microcantilever by a micropositioner. Typically, the quality factor is demonstrated increasing from 7.25 to 19.07, when the added mass is 22.82 ng. The mass loading size effect on the quality factor in the experiments has also been discussed. The discipline investigated here is meaningful for the contour design of the microcantilever used in air.