2014/08/06 by Robin M. Cole, Cole, Robin M., George A. Brawley +13 · 1 citation
Physics and Astronomy · Engineering · #Mechanical and Optical Resonators #Force Microscopy Techniques and Applications #Advanced MEMS and NEMS Technologies
paper · pdf · doi:10.48550/arxiv.1408.1281
Graphene mechanical resonators have recently attracted considerable attention\nfor use in precision force and mass sensing applications. To date, readout of\ntheir oscillatory motion has typically required cryogenic conditions to achieve\nhigh sensitivity, restricting their range of applications. Here we report the\nfirst demonstration of evanescent optical readout of graphene motion, using a\nscheme which does not require cryogenic conditions and exhibits enhanced\nsensitivity and bandwidth at room temperature. We utilise a high Q\nmicrosphere to enable evanescent readout of a 70 \μm diameter graphene drum\nresonator with a signal-to-noise ratio of greater than 25 dB, corresponding to\na transduction sensitivity of SN1/2 = 2.6 \× 10-13 m\n\Hz-1/2. The sensitivity of force measurements using this\nresonator is limited by the thermal noise driving the resonator, corresponding\nto a force sensitivity of Fmin = 1.5 \× 10-16 N\n\Hz-1/2 with a bandwidth of 35 kHz at room temperature (T = 300\nK). Measurements on a 30 \μm graphene drum had sufficient sensitivity to\nresolve the lowest three thermally driven mechanical resonances.\n