When
Thursday, April 24, 2025 at 4:00 p.m.
Constantine Megaridis
University Distinguished Professor
James P. Hartnett Professor of Energy Engineering
Director, Micro/Nanoscale Fluid Transport Laboratory
Department of Mechanical & Industrial Engineering
University of Illinois Chicago
"Surface Wettability Engineering: From Microfluidics to Thermal Management of Electronics"
AME Lecture Hall, Room S212
Zoom link
Abstract: Multi-scale interactions of liquids with solid surfaces are influenced by the thermophysical properties of the fluid, the morphology and chemical composition of the solid, as well as the dynamic and thermal characteristics of the process. Manipulating liquids on solid surfaces is frequently required in lab-on-chip microfluidics, phase-change heat transfer, and electronic chip cooling. We use scalable, surface-wettability engineering approaches to fabricate patterned substrates that comprise strategically-laid hydrophilic domains on less-wettable backgrounds. The spatial contrast of surface energy on the patterned substrates causes fast actuation of microliter droplets through hemiwicking and Laplace pressure-driven mechanisms. Examples are presented for rapid pumpless transport, splitting, merging and metered dispensing of liquid microvolumes on patterned lab-on-chip type substrates, ranging from paper and plastics, to glass and metals. Some of the designs facilitate self-driven transport even against gravity, thus being appropriate for 3-D microfluidics. The suitability of the present approach for enhancing dropwise condensation heat transfer is also demonstrated using contrasting wettability regions laid to control condensate nucleation and maximum droplet size, and facilitate pumpless condensate drainage from a cooled surface. Finally, a heat-spreading device, namely, a sealed vapor
chamber with only wettability-patterned components (no porous wicks) is presented as a functioning system that relies on the present approach for effective thermal management of high-power electronics.
Bio: Constantine Megaridis received his PhD in fluid/thermal sciences from Brown University and holds a MS in applied mathematics, also from Brown. He is a Fellow of the American Physical Society and the American Society of Mechanical Engineers. He was named James P. Hartnett
Professor of Energy Engineering in 2024, UIC Distinguished Professor in 2018, UIC Inventor of the Year in 2015 and University of Illinois Scholar in 2012. He has been awarded the Kenneth T. Whitby Award of the American Association for Aerosol Research. He has published over 150 journal papers, 250 conference papers and is co-inventor of 10 issued U.S. patents. His research has received continuous funding support from numerous federal and industrial sources for over three decades. His current research activities focus on fluid/particle transport, multiphase heat and mass transfer, multifunctional coatings and interfacial phenomena relevant to micro and nanotechnologies.