Fabrication of integrated microfluidic devices by direct ink writing (DIW) 3D printing

•A rapid and simple method of fabricating integrated microfluidic devices with DIW 3D printer.•Tunable channel dimensions as small as 32 (width) by 30 μm (height).•Simple fabrication of functional modalities such as valve and flow resistor.•Simple integration of functional substrates (e.g. PCB) and functional materials (e.g. microporous membranes).