Mass Sensing in a Liquid Environment Using Nonlinear Self-Excited Coupled-Microcantilevers

Development of an ultrasensitive mass sensor that can detect the single cell level with high accuracy in the viscous regime has attracted attention because it promotes the development of new drugs and the identification of disease biomarkers. Ultrasensitive mass detection in the viscous regime is investigated on the basis of the relative amplitude change in self-excited coupled microcantilevers. We have previously proposed self-excitation theoretically to directly detect the relative amplitude change, even in high viscosity environments, for which conventional methods based on external or forced excitation are inapplicable. The experimental results confirm quantitative mass sensing on the order of nanograms in water without any influence of spurious resonance peaks.