And here is my analysis of data on the same cantilever that I took:

Variable (units)              : mean +/- std. dev. (relative error)
Cantilever k (N/m)            : 0.0686691 +/- 0.00134223 (0.0195464)
photoSensitivity**2 (V/nm)**2 : 0.000333038 +/- 1.88694e-06 (0.00566586)
T (K)                         : 295.15 +/- 5.68434e-14 (1.92592e-16)
1/Vphoto**2 (1/V)**2          : 50598.9 +/- 946.564 (0.0187072)