Passive measurement of progressive mass change via bifurcation sensing with a multistable micromechanical system

Mass sensing using the onset and crossing of a dynamic bifurcation of a micromechanical system has been shown to reduce the mass threshold which may be detected and exhibited improved robustness to damping and noise compared to traditional tracking of resonant frequency shift. Previous investigations demonstrated that mass measurement over time via actively controlled strategies or explored passively operated threshold-type methods to indicate a pre-determined mass was adsorbed. Recently, an alternative idea integrating aspect of frequency shift- and bifurcation-based mass sensors and methods was proposed, providing initial illustration of a noteworthy ability to passively quantify progressive mass adsorption due to sequentially activated bifurcations. To advance the state of the art, this research provides a thorough investigation of this new sensing concept in terms of its dynamic characteristics and devises guidelines for effective, reliable operations. The conceptual foundation of the sensing method and an experimentally validated sensor model are reviewed. The results of numerous simulated operational trials and parametric investigations are detailed to reach important conclusions on sensor operations and versatility, and to uncover the influences of key operational conditions upon detection metrics. Finally, suitable microscale sensor architectures and fabrications are described to exemplify the flexibility of successfully realizing the mass sensing strategy.