Magneto-Mechanical MEMS Sensors for Bio-Detection

Ferromagnetic materials have shown to possess some unique and useful properties, one of which is that they are magnetomechanical transducers, that is, they exhibit a change in dimension when they are subjected to an external magnetic field and vice versa. This magneto-mechanical coupling enables magnetoelastic sensors to be driven to resonance via a modulated magnetic field to detect biological species via frequency shift by mass addition [1,2]. This work details the development of an algorithm to predict the number of captured

E. coli

cells based only upon the resonance frequency shift. This is an important issue as attaching cells influence resonance based upon their location on the sensor. It is therefore necessary to develop a statistical protocol to predict the concentration of the target agent present. A protocol was developed based upon data from microscale resonators using polystyrene beads as a simulant. The protocol was verified with numerical studies and experiments using

E. coli

cells.