Table 1.

Measured (Theoretically Calculated) Nonlinear Stiffness Coefficients λ_pq (10⁻⁵ nm⁻²) for the First Three Out-of-Plane Flexural Modes of the Doubly-Clamped NEMS Device^a

	q = 1	q = 2	q = 3
p = 1	0.53 ± 0.01 (0.53)	1.76 ± 0.36 (1.45)	3.51 ± 0.47 (3.59)
p = 2	0.18 ± 0.01 (0.186)	1.16 ± 0.03 (1.16)	1.77 ± 0.13 (1.65)
p = 3	0.13 ± 0.01 (0.124)	0.35 ± 0.06 (0.445)	1.43 ± 0.07 (1.43)

^aUncertainties originate from the linear fits to the measured response, e.g., see Figure 2b. Monitored modes (p); driven modes (q).