Figure 7: SEM micrographs at 45° viewing angle of a finely designed three-dimensional microfluidic mixer channel milled by using advanced dwell time control linked with the object filling algorithm applied to the pattern. Reprinted from [74]. The ability to create intricate 3D structures either by milling or deposition is perhaps the most recognized unique feature of IBL. In this example, the IBL-based fabrication of microfluidic mixer devices allows for sophisticated three-dimensional channel geometries that can be fabricated only by direct-write IBL.