Amplitude Difference Changes Based Metrological Scheme for Force Detection in A Mode-localized 5-beam Array

In this paper, amplitude difference changes (abbreviated as M _adc ) is proposed as a metrological scheme to characterize a coupled 5-beam array for force detection application for the first time. A new theoretical model, taking account of force perturbation effect on amplitude difference changes, is constructed with the 5-beam array. The proposed M _adc -based metrological scheme shows linear characteristics across a wider force range, compared to the conventional amplitude changes based one (abbreviated as M _ac ) with a monotonically increasing curve. When applying magnetic force perturbation lower than 0.5N, a sensitivity of 23.5% ( $\text {mm}\cdot \text {N}-1$ ) is estimated from the proposed M _adc -based scheme, 3.36 times of magnitude higher than that of 7% ( $\text {mm}\cdot \text {N}-1$ ) from the M _ac -based one. The amplitude difference changes as a linear function of the force perturbation is verified in the present coupled 5-beam array, but the proposed metrological scheme is believed to be also applicable to other multi-resonator array based force sensor devices.