A laterally resonating gravimetric sensor with uniform mass sensitivity and high linearity

In this paper, a laterally resonating gravimetric sensor with high linearity and uniform mass sensitivity is presented for biochemical sensor applications including rare-cell detection. The sensor utilizes symmetrically placed, balanced, folded spring beam structures to ensure lateral motion of the proof mass and limit the displacement difference between the proof mass center and edges. The dynamic mass sensitivity range of the resonator is increased by using the above mentioned properties of the resonators. It has been experimentally verified that the standard deviation in resonance frequency shift is 1.9% for different capture sites. It has also been experimentally shown that the sensors behave highly linearly for mass loads between 13 pg and 2700 pg.