Design of Optimized Microfluidic Devices for Viscoelastic Fluid Flow

In this work we present a fully automated procedure for design of microfluidic devices with optimal performance. The proposed approach combines a finite-volume viscoelastic flow solver, an optimizer, and an automatic mesh generation and adaptation procedure. The methodology can be used in the automatic search of the ideal shape of a given flow geometry, in order to achieve optimal performance. The procedure is fully automatic and general, and can be coupled with any computational fluid dynamics (CFD) solver. In this work we use a viscoelastic flow solver and apply the methodology in the design of two microfluidic devices with optimal performance under laminar flow conditions: (i) development of a microfluidic analogue of an electronic diode, which presents large anisotropic flow resistance in both flow directions; (ii) design of a microfluidic T junction that generates a strong extensional flow with a nearly constant strain rate along the centerline.