Atomic Force Microscopy Analysis of Velocity Dependent Adhesive Viscoelastic Contact

Adhesive contact phenomena play a crucial role in various scientific and engineering fields. However, considering viscoelasticity, which is essential for understanding practical applications involving soft materials like polymers, makes analysis challenging. Traditional elastic contact models such as the Johnson-Kendall-Roberts and Maugis-Dugdale models often fail to account for viscoelastic behavior. In this study, rate-dependent viscoelastic adhesive contacts were analyzed using atomic force microscopy force-distance curve measurements, comparing the elastic models with the viscoelastic model proposed by Barthel. The force curve analysis, conducted with the Barthel model for the first time, reveals that viscoelastic behaviors inside the contact area and the interaction zone both affect the contact state. These viscoelastic behaviors result in phenomena specific to viscoelastic contact, such as the "stick region" and the apparent work of adhesion. The Barthel model successfully captures the rate dependence of the contact situation, promoting a comprehensive understanding of viscoelastic adhesive contact phenomena.