Engineering with Droplets

Pallav Kant (Department of Earth Science) Cambridge Fluids Network - fluids-related seminars 13 October 2022 11:30am Open Plan Area, BP Institute, Madingley Rise CB3 0EZ Recent years have witnessed a surge in droplet-based technological innovations in manufacturing, medical diagnostics, chemical synthesis, material science, and even forensic science. This rapid progress is a result of the interdisciplinary research framework that accelerates both fundamental research and applications. In this talk, we will discuss the challenges in designing a robust, inkjet printing-based manufacturing process for display devices, as well as opportunities for fundamental fluid dynamics research. In particular, we will focus on the complexities arising from the spreading of microdroplets on patterned surfaces. The term 'patterned surfaces' refers to surfaces with either micron-sized topographical features, variations in wettability, or a combination of both. Using experiments and numerical modelling, we demonstrate that patterned surfaces provide an effective means to control the spread of fluid deposited using an inkjet method. Finally, time permitting, we will turn our focus to a mistake-led discovery of self-propelling droplets. I will demonstrate that a volatile droplet deposited on a uniformly heated substrate can spring into self-propulsion. Since the temperature of the substrate in such a scenario remains below the boiling temperature of the volatile liquid, this novel route to self-propulsion is not equivalent to the Leidenfrost effect!