A silicon cantilever beam is being considered for a mass sensor. the beam dimensions are L= 200 micro meter , w=50 micro meter and t= 3 micro meter. The properties of silicon are modulus of elasticity, E=160 GPa, and density=2.33 gm/cm^3. The sensor will operate in air and has a damping coefficient, b=10^-6 N-s/m. The surface of the beam has been functionalized to bond only with a particular chemical species. It is desired to be able to sense when 500 femtograms of this chemical lands on the beam. It is desired to design the beam sensor to operate at resonance with amplitude of 10nm, what driving force and driving frequency should be used?