Optically Accessible MEMS Resonant Mass Sensor for Biological Applications

Resonant measurement of mass has emerged as a powerful tool for cellular characterization in biological and medical research. For application in clinical diagnostics and development, in pursuit of large volumes of sample data, microfluidics become an essential conveyor for serial measurement. The nature of channel fabrication within a resonant structure often prohibits optical characterization and manipulation methods within its inner volume due to the opacity of constituent materials. This perpetuates a lost opportunity for simultaneous investigation with important optical techniques, including laser trapping, fluorescent microscopy, flow cytometry, and many other critical approaches. In an attempt to unify these technologies, we seek to maintain the optical availability of samples as they undergo resonant mass measurement. To the best of the authors' knowledge, the resulting device is the first optically-clear fluidic-enabled resonant structure that is scalable for large cellular study. As such, this paper describes the integrated sensor and its supporting system, accompanied by important specifications and metrics.