Analytic comparison of the sensitivities of bulk‐wave, surface‐wave, and flexural plate‐wave ultrasonic gravimetric sensors

We show that, for small added masses, the sensitivities of bulk‐mode, surface‐mode, and flexural plate‐mode gravimetric ultrasonic sensors are respectively 2/ρλ, ≊1/ρλ, and 1/2ρd, where ρ is the density of the sensor substrate material, λ is the wavelength, and d is the plate thickness of the flexural‐mode sensor.