G.A. Shaw, R.S. Gates, W.A. Osborn, M.J. McLean, J.J. Filliben
National Institute of Standards and Technology,
Keywords: metrology, calibration, reference cantilever, international system of units, force spectroscopy
Summary:NIST has produced a new standard reference material (SRM) for atomic force microscope (AFM) cantilever spring constant calibration. SRM 3461 is an array of 7 microfabricated silicon cantilevers with a spring constant range of approximately 0.03 N/m to 0.2 N/m. Each cantilever was characterized using a laser Doppler vibrometer (LDV) thermal method to establish uniformity. Traceability to the International System of Units (SI) was established by directly measuring the stiffness of a subset of cantilevers using the NIST electrostatic force balance (EFB). The test methods and uncertainty analysis performed to validate the traceability of the larger batch of cantilevers indicate agreement with the LDV method of less than 1 %, within the combined standard uncertainty of the measurements.