A Simple Technique to Readout and Characterize Coupled MEMS Resonators

Abstract

Highly sensitive microelectromechanical system (MEMS) resonators have been used for extensive applications like mass sensing. However, these arrays are prone to process variations and are difficult to characterize due to lack of connections with each resonator. Coupled array of such sensors can enhance functionality while reducing interconnections. This scheme allows a number of sensors to be read out using a single input/output channel. By perturbing the spring constant of one resonator, two sets of eigenvalues can be measured to reconstruct the system matrix of the coupled system. However, perturbation on MEMS devices can introduce non-linear or physical change. To prevent such undesired change, this paper proposes a technique to couple an electrical resonator to an array of MEMS resonators. Two sets of eigenvalues can therefore be measured by simply connecting/disconnecting the electrical resonator. Errors introduced by frequency noise, array size, coupling strength and damping have been analysed. The successful coupling between electrical and mechanical resonators brings huge promise for integrated MEMS devices that could be used for single input/output multisensor and monitoring variations in MEMS fabrication.

Coupled Piezoresistive Graphene Nano-Resonators

“…If the devices are identical, it is impossible to differentiate the origin of these changes. However, nanofabrication rarely, if ever, leads to identical devices [10][11][12]. This means that the inherent variability of the devices will enable one to uniquely determine which resonator has changed while measuring from any one of the resonators, thereby providing inherent mechanical multiplexing.…”

“…However, if one utilizes the effects of coupling rather than avoiding it, one may design mechanical multiplexing in arrays of nano-resonators by utilizing their collective behavior. It is feasible to design multisensing resonant devices by functionalizing different resonators with different sensing abilities [9][10][11][12][13]. Graphene structures are notoriously difficult to fabricate and no suitable transduction mechanism has been reported to utilize coupling in these structures.…”

Characterization of forced localization of disordered weakly coupled micromechanical resonators

“…It can be observed from Figure 5e Localization of disordered weakly coupled micromechanical resonators H Zhang et al veering point between the measured SRD line and the theoretical line is caused by the initial structural asymmetry of the weakly coupled resonators due to the fabrication tolerances. Although it is difficult to quantitatively estimate the stiffness and mass mismatches simultaneously, it is possible to use the obtained frequency and veering point information to identify one parameter between them if the other is assumed to be symmetric or has been precisely measured 42 . The vibrational energy proportions of Resonator 1 under the SRD and DRD schemes are shown in Figure 5f.…”

Ultra-Precise MEMS Based Bio-Sensors

“…In the past few years, in the MEMS community, a paradigm shift is observed in the design and implementation of micromechanical resonating sensors. A new perspective is presented in using 1-d chain of a coupled resonating proof masses, more familiarly refereed as multi degree-of-freedom (m-DoF) array, coupled resonator (CR) array, weakly coupled resonators (WCR) or mode-localized sensors [20][21][22][23][24][25][26][27][28]. Figure 1 shows a representative schematic for such system.…”