The Interaction between Micrometer-size Particles and Flat Substrates: A Quantitative Study of Jump-to-Contact

Abstract

The interaction force acting on an individual micrometer-size polystyrene particle near a flat, electrically conducting substrate has been measured by attaching the particle to an atomic force microscope cantilever. From the spatial dependence of the interaction force, the equations of motion governing a particle near the substrate can be determined. These considerations allow a prediction of the jump-to-contact distance of the particle as it approaches the substrate. This distance is measured as a function of particle radius and compared with predictions based on the relevant interaction force models.

Key Words:

• Particle adhesion
• atomic force microscope (AFM)
• surface force interaction
• jump-to-contact