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Soft adhesion is ubiquitous in everyday systems, yet the dynamic process by which soft solids initiate and grow contact with rigid solids remains poorly understood. This thesis investigates the dynamics of zero-load adhesive contact between a soft polydimethylsiloxane (PDMS) gel and a rigid glass microsphere using brightfield, high-speed imaging. We focus on early-time contact evolution from 10 milisecond to 1 second after initial contact. We observe a universal logarithmic growth in contact height across varying gel stiffnesses and sphere sizes, suggesting a thermally activated, defect-hopping mechanism similar to that seen in the adsorption of rigid spheres to liquid-liquid interfaces. As time progresses, the contact growth transitions to a slower regime dependent on stiffness and sphere size, pointing to additional contributions from viscoelastic and poroelastic dissipation. These results provide new insights into the fundamental physics of soft solid contact imitation and establish an experimental framework for future studies of soft adhesion dynamics.
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The Physics of Soft Adhesion
This review provides an introduction to the essential physics of soft adhesion, including the thermodynamics of adhesion and wetting, the mechanics of contact with deformable materials, and the material properties that most affect interfacial interactions with soft solid gels and elastomers. Throughout, we emphasize both foundational physics and current experimental and theoretical research in these areas. We conclude with a practical overview of standard experimental test methods for characterizing soft adhesion. The physical understanding developed in this article provides the basis for understanding the mechanics of contact with soft materials.
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- Award ID(s):
- 2129463
- PAR ID:
- 10673114
- Publisher / Repository:
- Annual Reviews
- Date Published:
- Journal Name:
- Annual Review of Condensed Matter Physics
- Volume:
- 17
- Issue:
- 1
- ISSN:
- 1947-5454
- Page Range / eLocation ID:
- 395 to 418
- Subject(s) / Keyword(s):
- adhesion contact mechanics wetting surface thermodynamics gels elastomers adhesion testing
- Format(s):
- Medium: X Size: 1.6MB
- Size(s):
- 1.6MB
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript
- Journal Article:
- https://doi.org/10.1146/annurev-conmatphys-031424-010035
