A method to quantitatively measure the elastic modulus of materials in nanometer scale using atomic force microscopy.

Area of Science:

• Materials Science
• Nanotechnology
• Mechanical Engineering

Background:

• Atomic Force Microscopy (AFM) is a powerful tool for surface characterization.
• Accurate measurement of elastic modulus is crucial for material science and engineering.
• Existing AFM nanoindentation methods require precise calibration for reliable results.

Purpose of the Study:

• To develop a quantitative method for measuring the elastic modulus of materials using AFM nanoindentation.
• To introduce a new parameter, cantilever-tip property α, for improved calibration.
• To validate the proposed method against conventional nanoindentation techniques.

Main Methods:

• The proposed method models cantilever deformation and tip-sample interaction as springs in series.
• It utilizes Sneddon's elastic contact solution and a new cantilever-tip property α.
• Calibration involves AFM tests on two reference materials with known elastic moduli.

Main Results:

• The cantilever-tip property α and cantilever sensitivity A were measured using polypropylene and fused quartz.
• These calibrated values were used to accurately determine the elastic modulus of acrylic.
• The measured elastic modulus of acrylic (3.24 GPa) showed excellent agreement with conventional nanoindentation.

Conclusions:

• The proposed AFM nanoindentation method provides a reliable and accurate approach for quantitative elastic modulus measurement.
• The new cantilever-tip property α simplifies and enhances the calibration process.
• This method offers a valuable tool for material characterization in various scientific and engineering fields.