Net-overhang coupled microcantilevers for sensitive mass detection

This paper presents a kind of net-overhang coupled microcantilevers for ultrasensitive mass detection. Because of the coupling through the net overhang, each cantilever would resonate in two different modes (in-phase and out-of-phase modes). Mass sensitivity of the structure based on relative changes of amplitude ratio between the two cantilevers' in-phase modes is nearly two orders greater than that based on traditionally used resonant frequency shifts. Furthermore, compared with ambient tests, results under vacuum condition demonstrate improved sensitivity and easier emergence of out-of-phase states. Besides, the amplitude ratios show better stability in comparison with the resonant amplitudes and this would contribute to a better detection resolution.