Subcategory: STEM Research
Kausiksankar Das - University of Maryland Eastern Shore
Co-Author(s): Habilou Ouro-Koura, Department of Engineering, University of Maryland Eastern Shore, 1, Backbone Road, Princess Anne, MD; Department of Mechanical, Aerospace and Nuclear Engineering, Rensselear Polytechnic Institute, Troy, NY; Ayobami Ogunmolasuyi, Department of Engineering, University of Maryland Eastern Shore, 1, Backbone Road, Princess Anne, MD; Thayer School of Engineering, Dartmouth College, 14, Engineering Drive Hanover, NH; Othman Suleimana, Department of Engineering, University of Maryland Eastern Shore, 1, Backbone Road, Princess Anne, MD
Here we report signiﬁcant enhancement in mixing in low Reynolds number and passive microﬂuidic ﬂows by creating asymmetric boundary conditions introduced by periodic hydrophobic regions. Mixing in microchannels is necessary for effective operation of any microfluidic reactors, but mixing is very difficult to achieve in those length scales, thanks to the weak nonlinear inertial effects at low Reynolds numbers. We assert that a correlation exists between slip surface periodicity and their geometries with mixing in straight microchannels numerically, and compared it with experimental observations. Furthermore, we show that mixing parameter is explicitly dependent on the geometry of the hydrophobic regions. We have observed two different types of mixing mechanisms: 1) mixing through Baker type transformation, where the component fluids are stretched and folded, decreasing effective striation length, and 2) mixing through chaotic advection, where counter rotating eddies help rapid mixing of the component fluids. We hypothesize that in straight channels periodic stick-slip boundary conditions suddenly make transition of streamline properties across the stick-slip boundaries and introduce mixing in the ﬂow.
Funder Acknowledgement(s): National Science Foundation HBCU-UP award # 1719425; USM-LSAMP @ UMES program is supported by the National Science Foundation under Grant #HRD 1619676; Department of Education, MSEIP CCEM grant # P120A001768
Faculty Advisor: None Listed,
NSF Affiliation: HBCU-UP