CAREER: Inertio-Capillary Dynamics of Particles at Interfaces

This award supports integrated experimental and theoretical research on the motion of solid particles at a fluid interface. At sufficiently small scales, the effects of surface tension on particle motion can become important, for instance in allowing a paper clip to float on the surface of water despite being denser. While such static scenarios are well characterized generally, analogous dynamic scenarios arise throughout industry and nature (such as an airborne pollutant particle impacting a rain drop) and are far less studied. Insight into such particle dynamics at interfaces is critical to advancements in a range of technological applications, including pollution control, rapid manufacturing, biotechnology, and biomimetic and interfacial robotics. The planned research will be closely integrated with education and outreach activities including introducing undergraduate research experiences into the engineering curriculum and hands-on workshops in partnership with local camps and public libraries. This award supports a broad effort to expand the knowledge of particles at fluid interfaces in the intermediate inertio-capillary regime, situated between the more well studied static equilibrium capillary regime and the large-scale inertially dominated regime. The targeted problems of focus include particle impact, interface-bound particle dynamics, and self-propulsion and collective motion of driven interfacial particles. The research effort will combine novel state-of-the-art experiment with first-principle modeling techniques, and establish a coherent and consistent physical understanding for each of the specific research problems. In addition to the research findings, custom experimental designs and protocols, as well as pedagogical materials, developed as part of this work will be shared openly and thus translatable for use in other research, instruction, and demonstration contexts. The overall research efforts will be closely integrated with the development of an Engineering CURE (Course-based Undergraduate Research Experience) course. In other fields, it has been shown that such courses allow students to develop comparable levels of tangible and intangible skills as to traditional mentored research experiences but be more inclusive and diverse. Furthermore, the research activities will directly translate to hands-on demonstrations and workshops that will be executed in partnership with local camps, libraries, and other organizations, with an emphasis on engaging underrepresented groups in science and engineering. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.