Polymer-based device for efficient mixing of viscoelastic fluids

We demonstrated rapid mixing of viscoelastic fluids in microchannels constructed based on polymethyl methacrylate. Viscoelastic mixing without diffusion was achieved with an effective mixing length of less than 5 mm and a relatively fast flow rate. With an abrupt contraction microgeometry (8:1 contraction ratio), we mixed two different viscoelastic fluids experimentally at very low Reynolds numbers, but enormous Peclet and elasticity numbers. This special geometrical configuration triggers flow instability, leading to turbulent and efficient mixing. This flow regime has negligible inertia effects but significant elastic effects.