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% (mm·N-1) is estimated from the proposed M_adc-based scheme, 3.36 times of magnitude higher than that of 7% (mm·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.