Fig. 2.

STR using templates produced by direct laser writing. a Polymeric DNA double-helix (scale: 500 µm). b Inverse structure in fused silica glass (scale: 400 µm). The smallest channel size is 20 µm. c Intertwined spirals (scale: 900 µm). d Resulting intertwined microfluidic spiral channels in fused silica glass with a channel width of 74 µm. The channels were filled with dyes (see inset, scale: 140 µm). e Polymeric microstructures of an out-of-plane mixer structure (scale: 600 µm). f Microfluidic mixer structure in fused silica glass with a channel width of 74 µm (scale bar: 280 µm). As can be seen the 3D structures can be replicated with high fidelity and no deformations