Fig. 7.

Beam steering for cells and particles. (A) Schematic of a traditional, three-input design for creating a laminar-flow hydrodynamic jet in a channel. The first element in the channel is a simple birefringence medium followed downstream by longer element with the same characteristics but having the opposite angle. (B) Wide angle composite image showing steering of a jet of 2.7-μm-diameter beads streaming through two microfluidic metamaterial elements and refracting, and the interface between them. Note that in the second longer element, the bead path crosses over the original input position. (C Left) A similar device designed to bump blood lymphocytes, but not blood platelets, was used to demonstrate refraction of a stream of cells (α = 11.3°, G = 8 μm, λ = 11 μm). Depicted is time exposure showing the separation of lymphocytes, which track along the array axis, and platelets and residual labeling dye that follow the fluid flow direction. (C Right) Refraction of lymphocytes at the interface between +α and −α array elements (see Movie S3). The flow of the platelets and dye is undisturbed.