Laser Doppler Vibrometer Microscope

Since 2006, the Nanomechanical Properties Group has pioneered the use of Laser Doppler Vibrometry (LDV) to calibrate the stiffness of AFM cantilevers using the Thermal Method.  The instrument, a Polytec MSA-500 microscope vibrometer has been augmented with upgraded hardware, software, and environmental capabilities to provide superior sensitivity and accuracy of measurement.  The main focus has been on combining vibrational spectra of cantilevers with the Equipartition Theorem to extract accurate measurements of cantilever stiffness.  A series of publications over the past 15+ years has documented the careful development of this capability for a wide range of cantilever types and stiffness.  The crowning achievement has been the release in January of 2023 of NIST SRM 3461 which is a cantilever array artifact calibrated using this LDV and certified for stiffness values with uncertainties better than ± 3%.

Related Publications 

1. R. S. Gates, J. R. Pratt, "Prototype Cantilevers for SI Traceable NanoNewton Force Calibration" Measurement Science and Technology, Vol. 17, pp. 2852-2860, (Sep, 2006), (Institute Of Physics, Measurement Science &Technology Outstanding Paper Award 2006)
2. Z. Ying, M. Reitsma, R. S. Gates, "Direct Measurement of Cantilever Spring Constants and Correction of Cantilever Irregularities Using an Instrumented Indenter" Review of Scientific Instruments, Vol. 78, No. 6, 63708 pp., (01-Jun-2007) 
3. R. S. Gates, M. Reitsma, "Precise AFM Cantilever Spring Constant Calibration Using a Reference Cantilever Array" Review of Scientific Instruments, Vol. 78, (01-Sep-2007) 
4. R. S. Gates, M. G. Reitsma, J. A. Kramar, & J. R. Pratt “Atomic Force Microscope Cantilever Flexural Stiffness Calibration: Toward a Standard Traceable Method” Journal of Research of the National Institute of Standards and Technology, 116, 703-727 (2011)

5. R. S. Gates & J. R. Pratt “Accurate and Precise Calibration of AFM Cantilever Spring Constants Using Laser Doppler Vibrometry,” Nanotechnology, 23, 375702 (2012)

6. R. S. Gates, W. A. Osborn, & J. R. Pratt, “Experimental Determination of Mode Correction Factors for Thermal Method Spring Constant Calibration of AFM Cantilevers using Laser Doppler Vibrometry,” Nanotechnology, 24, 255706 (2013)
7. R. S. Gates, W. A. Osborn, and G. A. Shaw, Accurate Flexural Spring Constant Calibration of Colloid Probe Cantilevers using Scanning Laser Doppler Vibrometry," Nanotechnology 26 235704 (2015)
8. R. S. Gates, "Experimental confirmation of the atomic force microscope cantilever stiffness tilt correction," Review of Scientific Instruments, 88, 123710 (2017) https://doi.org/10.1063/1.4986201
9. R. S. Gates, W. A. Osborn, M. J. McLean, G. A. Shaw, & J. J. Filliben, "NIST Special Publication 260-227, Certification of Standard Reference Material® 3461 - Reference Cantilevers for AFM Spring Constant Calibration," (2022) https://doi.org/10.6028/NIST.SP.260-227