Flows in Microchannels and Cavities – Visco-Elasticity, Faradaic Charging and Surface Roughness Effects

Abstract:

Two phenomena for flows in microchannels, namely visco-elastic instability and Faradaic charging effects, are discussed. Aqueous solutions, which do not exhibit elastic behaviors, will behave visco-elastically with the addition of a small amount of polymers. Visco-elastic flow instability which promote mixing has been observed in the flow of these visco-elastic solutions through a constriction in microchannels. In addition, we recently show experimentally the existance of Faradaic charging in AC-electrokinetic (ACEK) flow. Lastly, surface roughness effects in micro- plastic injection molding are highlighted. The micro-injection molding process involves the flow of polymer melt in micro-cavities. Our recent investigations demonstrate that the flow model for macro-cavities could be employed satisfactorily to simulate the flow in micro-cavities if roughness effects are considered in an appropriate manner.

• Periodical: Advanced Materials Research (Volume 74)
• Pages: 73-76
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.74.73
• Online since: June 2009
• Authors: Yee Cheong Lam
• Keywords: Faradaic Charging, Injection Molding, Micro-Channel, Mixing, Surface Roughness (SR), Visco Elasticity

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