Time:April 18 2025, 13:00-14:00
Location: FENS G015
Abstract:Cavitation is the process of generating, expanding, and quickly collapsing bubbles in a liquid media. Cavitation bubbles are initiated when the pressure of a liquid decreases to a level lower than the saturation vapor pressure. Acoustic cavitation (AC) and Hydrodynamic Cavitation (HC) are two types of cavitation that have gained interest due to their efficiency and simplicity in application for bubble formation. Research on the microscale HC (“HC on a chip” concept) has been conducted since the mid-2000s, with a particular focus on the impact of small size on flow patterns and the initiation of cavitation. Recent studies have demonstrated that surface topology and device geometry play a crucial role in inducing cavitating flows. They contribute to the earlier inception of cavitation, intensify the development of cavitating flows, and generate a greater amount of energy from the collapse of bubbles. In this talk, “HC on a chip” concept will be discussed in 3 main pillars (a) Understanding the physics of cavitation in microscale; (b) Designing and fabricating novel microfluidic devices equipped with surface roughness for cavitation studies; (c) Identifying the role of cavitation process in liquid phase exfoliation, wastewater treatment and biomedical applications. In particular, the nature of the bubble collapse in the microscale cavitation and their similarities/differences with the macroscale compartments and acoustic cavitation are the fundamental aspects that will be discussed in this talk. The physics of key parameters, e.g., inception, dynamics, free radical production, shock waves, shedding mechanisms and shear forces, are substantially different in microscale and their effcets could be varied in the absence and presence of solid particles such as Graphene (G). We will discuss how uncovering their effects will advance our understanding of the microscale HC process, as well as the underlying mechanisms and physics of cavitation in conventional HC.
Bio:Dr. Morteza Ghorbani is a researcher at Sabancı University, and he currently heads the Cavitation and Interfaces Group (CAVinTace). He received his PhD degree from Mechatronics Engineering Department at Sabancı University in 2017. Later, Dr. Ghorbani undertook postdoctoral work at KTH Royal Institute of Technology, Stockholm, Sweden. In 2020, he moved to Sabancı University-SUNUM where became the principal investigator on microfluidics and cavitation while acting as a visiting researcher in the Medicine Technology and Health System School at KTH Royal Institute of Technology till 2022. Dr. Ghorbani has extensive experience in micro/nanofabrication, cavitation research, advanced mechanical characterization, high-speed shadowgraphy and PIV, laser diagnostics, and spectroscopy. He was the first globally to design and fabricate microfluidic devices capable of generating hydrodynamic cavitation and to withstand high-pressures by developing a robust process flow. He acts as an editor in Biomed Research International Journal, and he reviews for several journals including Physics of Fluids. He received a BAGEP Outstanding Young Scientist award from the Science Academy of Turkey in 2023 and a TUBA GEBIP Outstanding Young Scientist award from the Academy of Sciences of Turkey in 2024 for his studies and achievements. He was awarded (2023) the highly prestigious Newton Fellowship from The Royal Society (UK) to develop a hybrid exfoliation reactor. He also founded the spin-off CAViTreat AB after winning the Water Council's Tech Challenge in 2021 (USA) for his cavitation-based wastewater treatment innovation.