Coaxial atomic force microscope probes for imaging with dielectrophoresis

Area of Science:

• Physics
• Materials Science
• Nanotechnology

Background:

• Atomic Force Microscopy (AFM) is a high-resolution surface imaging technique.
• Artifacts can limit the accuracy and resolution of AFM images.
• Dielectrophoresis (DEP) is a phenomenon used to manipulate dielectric particles with non-uniform electric fields.

Purpose of the Study:

• To demonstrate AFM imaging enhanced by dielectrophoresis (DEP) using coaxial probes.
• To investigate the effect of DEP on spatial resolution and artifact reduction in AFM.
• To develop a theoretical model for DEP interactions with coaxial probes and dielectric samples.

Main Methods:

• Utilized coaxial probes in an Atomic Force Microscope setup.
• Applied dielectrophoresis (DEP) by using an electric field.
• Developed an analytical model for DEP forces between a dipole (coaxial probe), dielectric spheres, and a dielectric substrate.
• Acquired AFM images of dielectric spheres with and without applied electric fields.

Main Results:

• DEP provided force contrast, enabling enhanced spatial resolution in AFM imaging.
• AFM imaging with DEP significantly reduced or eliminated artifacts observed in conventional imaging.
• Experimental results showed quantitative agreement with the developed DEP model.
• Demonstrated successful imaging of dielectric spheres using DEP-enhanced AFM.

Conclusions:

• Dielectrophoresis (DEP) is an effective method for enhancing spatial resolution in AFM imaging.
• DEP-assisted AFM imaging minimizes artifacts, leading to more accurate surface characterization.
• The developed theoretical model accurately predicts DEP interactions, validating the experimental approach.