| 초록 |
When a droplet sits on a soft gel surface, its surface tension deforms the underlying material, creating a wetting ridge. Wetting ridge formation affects, besides static wetting, dynamic wetting behaviors. However, the underlying mechanisms are still largely unexplored mostly due to limitations in observation. Here, we directly visualize wetting ridges in real-time during spreading using x-ray microscopy with high spatial and temporal resolutions. We clearly show that ridge-growth dynamics is closely linked to the spreading regimes. Finally, we discuss spreading mechanisms on soft surfaces based on ridge-growth dynamics that determines ridge-geometry. We believe that our results would shed light on understanding of dynamic wetting behaviors on soft solids (e.g. contact angle hysteresis or evaporation) and be also potentially important to interpret complex biological processes on or in soft tissues (e.g. cell-substrate interactions). |
