Hollow Lamé mode MEMS mass sensors with 10 ppb-range stability for particles counting and weighing in fluid

This paper reports hollow MEMS plate oscillators for mass sensing in liquid with an extracted mass resolution of 7 femtograms. The sensors performances show a one-fold improvement compared to previous alike structures − 10,000-range Q factor and ppb-range frequency stability. These devices are connected through a customized plug and play test platform and do not need to work in a vacuum-sealed package. These performances, reached in ambient conditions whether the embedded channel is filled with air or water, make the devices potentially amenable to individual particles metrology from a few 10 nm up to the µm diameter range.