Forced detachment of immersed elastic rubber beads

Area of Science:

• Soft Matter Physics
• Adhesion Science
• Fluid Dynamics

Background:

• Understanding the adhesion and detachment of elastic materials is crucial in various fields, including microelectronics, biomedical engineering, and soft robotics.
• The behavior of elastic objects adhering to surfaces in viscous environments is complex and not fully understood, especially concerning the detachment dynamics.

Purpose of the Study:

• To investigate the adhesion strength and detachment dynamics of elastic beads on a solid surface submerged in a viscous liquid.
• To elucidate the distinct stages involved in the unbinding process and their underlying physical mechanisms.

Main Methods:

• Utilized elastic beads with a Young's modulus of approximately 1 MPa, initially compressed on a horizontal solid surface.
• Imposed detachment by applying fast vertical stretching above a specific threshold.
• Monitored the decrease in contact radius using interferential microscopy.

Main Results:

• Observed a three-step detachment process: fast elastic decompression, slow adhesive detachment, and catastrophic rupture.
• The contact radius decrease was quantitatively monitored throughout the detachment process.
• The observed dynamics were interpreted through the lens of energy transfer from Johnson Kendall Roberts (JKR) adhesion to viscous dissipation.

Conclusions:

• The detachment of elastic beads from solid surfaces in viscous liquids is a multi-stage process.
• Energy transfer to viscous losses near the rubber/solid/liquid contact line plays a significant role in the detachment dynamics.
• The findings provide insights into the interplay between elastic energy, adhesion, and viscous dissipation during interfacial separation.