Suspended micro/nano channel resonators: a review

Micro- and Nano- electromechanical systems (M/NEMS) have demonstrated outstanding sensing capabilities down to the yoctogram (10^(-24) g) scale in vacuum environment and cryogenic temperatures. In order to bring such extraordinary resolution levels into the study of biological processes, Suspended Microchannel Resonators (SMRs) have been developed. SMRs are hollow devices allowing for fluidic confinement inside the body of the resonator, which can thus be kept in dry environment or encapsulated in vacuum. Analyte binding and flow-through experiments can be performed, these latter enabling single-cell analysis. In this paper, we survey the progress of over the past 20 years in the field of SMRs. We review the main fabrication, transduction and packaging strategies. We also provide an insight into the working principle of the sensors and their applications to microfluidics and biology.