Grant: Discovery Grants Program - Individual

The proposed research is a unique program that seeks to understand the behavior of complex droplets and their interactions with surfaces. Specifically, it will tackle areas of drop motion on a surface when there is condensation; capture and release of droplets using shape memory material; and core-shell drop impact onto surfaces. This research can produce the necessary knowledge to enable advanced technologies of strategic importance today, such as, energy systems (e.g., efficient condensers, and water harvesting from air to meet UN's SDG goals), biotechnology (e.g. accurate dispensing and retrieval of droplets in drug discovery process), or mitigating insect fouling that is important for optical sensors in autonomous vehicles, or laminar wing technology needed for green aviation. A comprehensive study of condensate drops' shedding, exposed to a shearing airflow, will be done. The shedding is facilitated by micro-cone decoration of the surface, or use of electrowetting (EW) to promote dropwise condensation that is an order of magnitude more effective than film-wise condensation. We will seek relations between drop shedding, and heat transfer for each of the above strategies. We seek to understand the role of electrode design for EW, and micro-cone size, placement and interactions with shearing airflow to develop fundamental knowledge needed to design such systems for surfaces of different hydrophobicity. Gaining fundamental knowledge about how to capture and release droplets is the key to advance diagnostic, and drug discovery processes as well as microfluidic systems. To date the methods has been either to capture or release a droplet, but not both without elaborate auxiliary systems. We will use elasto-capillary phenomenon in conjunction with shape memory material to develop a method to achieve both capture and release of a droplet without the need for complex auxiliary systems. Study of droplet impact onto a surface, when the core-shell droplet is made of two immiscible liquids is important for technologies such as cell printing. The goal is to understand impact morphology (e.g., splash limits, spreading, and liquid-liquid interactions) as a function of surface wettability and liquid viscosity. We will extend this work to cases where the shell is made of a thin brittle solid and core is liquid. Such system can be a first order analogue of an insect (insects are exoskeleton creatures with hemolymph enclosed). This work will lay the foundational knowledge that is needed to mitigate insect fouling, and a first of its kind. This proposal, at its core, is designed to provide training for 20 students at different levels by adhering to EDI principles. They will gain skills needed for Canada's knowledge based economy by working on advanced imaging systems, surface fabrication and characterization, as well as analytical and modeling techniques. Communication skills will be honed through disseminating their findings.