Integrated MEMS/NEMS Resonant Cantilevers for Ultrasensitive Biological Detection

Table 2

Measured mass induced frequency shift, mass sensitivity, Allan variance (a standard parameter to evaluate resonant-frequency instability over a certain period of time) and sensing resolution for different modes of the cantilevers. The designed mass sensitivity, the calculated Allan variables based on measured frequency stability, and the finally obtained mass-sensing resolution based on the Allan variables analysis, are all listed for the corresponding cantilevers in corresponding resonant modes.

Cantilever type	No. 1	No. 2	No. 3	No. 4
Δ𝑓 (Hz)	57.5	591.2	443	2330
Sensitivity (Hz/pg)	0.33	4.3	0.9	5.1
Allan variance	2.1e-6	3.3e-7	7.6e-7	1.8e-7
Mass resolution (fg)	313	29	23	9