Stephen Speyer III
Research Mentor(s): Solomon Adera
Mentor Department: MechE
Authors: Solomon Adera, Michale Remer, Biruk Teka
Session: Session 6 (3:00pm – 3:50pm)
Presentation Type: Poster 18
Abstract
This study investigates air bubble entrapment during droplet impact on microstructure silicon surfaces in relation to the effect of varying pillar diameter and center-to-center distance. High-speed imaging was used to analyze the influence of these geometrical parameters on the formation and distribution of air bubbles. The results of our study demonstrate that, rather than one central bubble, microstructure surfaces enable the air pocket to be redistributed into several small bubbles, which become trapped between and atop the pillars. This redistribution implies that microstructures provide extra pathways for the entrapped air, and hence the air entrapment dynamics are modified. Furthermore, from a top-down perspective, the fully flattened droplet assumes a square-rounded shape, with this increasingly becoming more distinct with reducing pillar spacing. The edges of the droplet become more pronounced, tightly tracing the underlying microstructure, and further emphasizing the significance of the microstructure in controlling impact behavior. These findings are consistent with theoretical arguments in fluid dynamics and further emphasize the significance of microstructure design in the manipulation of liquid-solid interactions. The results have important implications for the optimization of surface engineering in a wide range of applications, including inkjet printing, gear lubrication, cooling technologies, and biomedical fluid control.
