Calibration of the spring constants of atomic force microscopy (AFM) cantilevers is one of the issues in biomechanics and nanomechanics for quantified force metrology at pico- or nano Newton level. In this paper, we present an AFM cantilever calibration system: the Nano Force Calibrator (NFC), which consists of a precision balance and a one-dimensional stage. Three types of AFM cantilevers (contact and tapping mode) with different shapes (beam and V) and spring constants (42, 1,0.06 N m') are investigated using the NFC. The calibration results show that the NFC can calibrate the micro cantilevers ranging from 0.01 - 100 N rn" with relative uncertainties ofless than 2%.
