title: Joule heating effects on electroosmotic entry flow.
abstract: Electroosmotic flow is the transport method of choice in microfluidic devices over traditional pressure-driven flow. To date, however, studies on electroosmotic flow have been almost entirely limited to inside microchannels. This work presents the first experimental study of Joule heating effects on electroosmotic fluid entry from the inlet reservoir (i.e., the well that supplies fluids and samples) to the microchannel in a polymer-based microfluidic chip. Electrothermal fluid circulations are observed at the reservoir-microchannel junction, which grow in size and strength with the increasing alternating current to direct current voltage ratio. Moreover, a 2D depth-averaged numerical model is developed to understand the effects of Joule heating on fluid temperature and flow fields in electrokinetic microfluidic chips. This model overcomes the problems encountered in previous unrealistic 2D and costly 3D models, and is able to predict the observed electroosmotic entry flow patterns with a good agreement.
authors.affiliation: Department of Mechanical Engineering, Clemson University, Clemson, SC, USA.
authors.forename: Rama Aravind
authors.initials: RA
authors.lastname: Prabhakaran
authors.affiliation: Department of Mechanical Engineering, Clemson University, Clemson, SC, USA.
authors.forename: Yilong
authors.initials: Y
authors.lastname: Zhou
authors.affiliation: Department of Mechanical Engineering, Clemson University, Clemson, SC, USA.
authors.forename: Saurin
authors.initials: S
authors.lastname: Patel
authors.affiliation: Department of Mechanical Engineering, Clemson University, Clemson, SC, USA.
authors.forename: Akshay
authors.initials: A
authors.lastname: Kale
authors.affiliation: College of Marine Engineering, Dalian Maritime University, Dalian, P. R. China.
authors.forename: Yongxin
authors.initials: Y
authors.lastname: Song
authors.affiliation: LNM, Institute of Mechanics, Chinese Academy of Sciences, Beijing, P. R. China.
authors.forename: Guoqing
authors.initials: G
authors.lastname: Hu
authors.affiliation: Department of Mechanical Engineering, Clemson University, Clemson, SC, USA.
authors.forename: Xiangchun
authors.initials: X
authors.lastname: Xuan
mesh_terms: D003198:Computer Simulation; D053841:Electroosmosis; D006358:Hot Temperature; D008962:Models, Theoretical
keywords: Electrokinetic; Electroosmosis; Electrothermal flow; Entry flow; Joule heating