SI-Traceable Spring Constant Calibration of Microfabricated Cantilevers for Small Force Measurement
Gordon A. Shaw, John A. Kramar, Jon R. Pratt
A variety of methods exist to measure the stiffness of microfabricated cantilever beams such as those used as mechanical sensors in atomic force microscopy (AFM). In order for AFM to be used as a quantitative small force measurement tool, these methods must be validated within the International System of Units (SI). To this end, two different contact techniques are explored. First, a novel dynamic indentation-based method was used to measure the spring constant of a rectangular cantilever beam. These results were then compared against an SI-traceable measurement from an electrostatic force balance (EFB). The measurements agree within experimental uncertainty, within 2% for spring constants greater than 2 N/m. The use of this cantilever beam as a transfer artifact for in-situ AFM cantilever calibration was then evaluated in comparison to the thermal calibration method. Excellent agreement is seen between these techniques, confirming the consistency of the thermal method with SI-traceable contact calibration.
, Kramar, J.
and Pratt, J.
SI-Traceable Spring Constant Calibration of Microfabricated Cantilevers for Small Force Measurement, Experimental Mechanics, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=822356
(Accessed February 29, 2024)