Fig. 4: Gate tuning of frequency and dissipation characteristics and material characterization for two singly-isolated 2D MoS₂ drumhead NEMS resonators with nonuniform membrane profiles.

a–k Characterization of Device S3. SEM images of Device S3 showing (a) the suspended membrane diameter of 6 μm with contact electrodes, (b) the zoom-in region in (a) showing the wrinkle, and (c) the zoom-in region in (b) showing the residue on the suspended membrane. d Photoluminescence spectrum. e Raman spectrum showing that the peak separation between the E_2g¹ and A_1g peaks is 21.81 cm⁻¹, corresponding to bilayer MoS₂. f Frequency tuning characteristics measured by varying V_GS from 0 V to 20 V with a fixed v_RF of 20 mV, with the amplitude shown in color scale. g Measured linear to nonlinear resonances by varying v_RF from 25 mV to 200 mV with a fixed V_GS of 5 V. h–k Extraction of Q factors at varying gate voltages, showing (h) fitting to the resonance at V_GS = 5 V, and (i) fitting to the resonance at V_GS = 10 V. Summary of the measured Q factor and fitting to the dissipation model at varying (j) V_GS, and (k) v_RF, from which δ of 0.09 is extracted. l–v Measured characteristics of Device S4, with a diameter of 4 μm, shown in the same sequence as in (a–k). The SEM images in (l–n) also show some wrinkles. The measured Raman peak separation of 20.11 cm⁻¹ in (p) corresponds to monolayer MoS₂. From fitting to the measured gate tuning of the Q factor, a δ of 0.1 is extracted