A compact torsional reference device for easy, accurate and traceable AFM piconewton calibration

Area of Science:

• Nanotechnology
• Metrology
• Materials Science

Background:

• Atomic Force Microscopes (AFM) enable nanomechanical testing of materials and single molecules.
• Existing AFM force calibration methods lack sufficient accuracy and traceability.
• Accurate force calibration is essential for reliable nanomechanical measurements.

Purpose of the Study:

• To present a novel force reference device for calibrating AFM microcantilevers.
• To achieve highly accurate and repeatable calibration of normal cantilever stiffness.
• To establish traceability to the International System of Units (SI) for AFM force measurements.

Main Methods:

• Development of a force reference device for AFM cantilever calibration.
• Calibration of cantilever normal stiffness down to 90 pN/nm.
• Traceable calibration to SI units via the ampere and metre, bypassing kilogram traceability.

Main Results:

• The device enables accurate and repeatable calibration of AFM microcantilever stiffness.
• Achieved calibration uncertainty better than 3.5% for traceable measurements.
• Demonstrated a method for SI traceability avoiding kilogram-based calibration challenges.

Conclusions:

• The presented force reference device significantly improves AFM force calibration accuracy and traceability.
• This method provides a reliable alternative for SI-traceable force calibration in nanotechnology.
• Further improvements in uncertainty are possible, paving the way for enhanced nanomechanical testing.