An acoustic impedance model has been developed for analysis of response mechanisms of piezoelectric biosensors.The non-gravimetric effect in sensor's responses was defined by a parameter named acoustic correction factor relating to the mechanic property(shear modulus)of the sensor loading.Under some approximate conditions,response equations of piezoelectric biosensors were consequently derived for various loadings involving viscous liquid,rigid and viscoelastic films in gas and liquid phases.It was shown th...