An atomic force microscope (AFM) calibration experiment is conducted to measure the vertical deflection $\delta$ of a micro-fabricated silicon cantilever when a micro-mass $m$ is deposited on its free end. The relation between the deflection and the mass is given by:

$$\delta =\frac{\Gamma m}{E}$$

where $E$ is the Young modulus of the cantilever material and $\Gamma$ is a calibration constant.

A graph of the cantilever's vertical deflection $\delta$ (in $\mu m$) against the deposited mass $m$ (in $\mu g$) yields a straight line passing through the origin. From the line of best fit, a mass of $m=2.5\mu g$ corresponds to a vertical deflection of $\delta =0.35\mu m$.