Calibration of Microfabricated Cantilevers for SI-Traceable Small Force Measurement
Gordon A. Shaw, Jon R. Pratt, John A. Kramar
A procedure is described by which the spring constant of a microfabricated cantilever beam can be calibrated for the measurement of small forces in an atomic force microscope (AFM) or other device. The procedure utilizes dynamic force instrumented indentation to determine the mechanical properties of the beam by apply a well-characterized oscillating force and measuring resulting displacement of the system. An uncertainty analysis is carried out, and by intercomparison with the U.S. National Institute of Standards and Technology (NIST) Electrostatic Force Balance, the spring constants determined using the new method agree within 2% for spring constants as low as 2 N/m.