Fig. 5: Sensing characteristics of rectangular and trapezoidal stepped piezo-cantilever resonators.

a Frequency responses of different resonators under the 2nd and 3rd flexural modes in n-hexane and D4 medium. b, c The measured resonant frequency and Q-factor of the rectangular stepped piezo-cantilever resonator are the function of the liquid density and viscosity, separately. d, e The measured resonant frequency and Q-factor of the trapezoidal stepped piezo-cantilever resonator are the function of the liquid density and viscosity, separately. The error bars represent the standard deviation of the averaged frequencies.