the present embodiment describes a laminar - mixing embodiment that utilizes simple , three - dimensional injection . also described is the use of the embodiment in combination with wide and shallow sections of channel to affect rapid mixing in microanalytical systems . the shallow channel sections are constructed using all planar micromachining techniques , including those based on isotropic etching . the planar construction enables design using minimum dispersion concepts that , in turn , enable simultaneous mixing and injection into subsequent chromatography channels .