After reading the abstract on the resonanting cantilever mass detector, I think this paper might be of interest to some.  My colleagues and I wrote this for a MEMS device class we took Fall 2005 at Columbia University while I was an undergraduate.  It was a term design project.

Abstract – Micro-electromechanical systems (MEMS) often provide cost effective 

We recently reported the mass sensing by using resonating microcantilevers. The characterization of mass-sensing and its related sensitivity was suggested on the basis of elasticity theory. This work was published online at Sensors and Actuators A (click here).