[Analytical Chemistry] One step fabrication of a microfluidic device with an integrated membrane and
One of the largest impediments in the development of microfluidic-based smart sensing systems is the manufacturability of integrated, complex devices. Here, we propose multimaterial 3D printing for the fabrication of such devices in a single step. A microfluidic device containing an integrated porous membrane and embedded liquid reagents was made by 3D printing and applied for the analysis of nitrate from soil. The manufacture of the integrated, sealed device was realised as a single print within 30 min. The body of the device was printed in transparent acrylonitrile butadiene styrene (ABS), and contained a 400 μm wide structure printed from a commercially available composite filament. The composite filament can be turned into a porous material through dissolution of a water-soluble material. Liquid reagents were integrated by briefly pausing the printing before resuming for sealing the device. The devices were evaluated by the determination of nitrate in a soil slurry containing zinc particles for the reduction of nitrate to nitrite using the Griess reagent. Using a consumer digital camera, the linear range of the detector response ranged from 0-60 ppm, covering the normal range of nitrate in soil. To ensure the sealing of the reagent chamber is maintained, aqueous reagents should be avoided. When using the non-aqueous reagent, the multimaterial device containing the Griess reagent could be stored for over 4 days but increased the detection range to 100-500 ppm. Multimaterial 3D printing is a potentially new approach for the manufacture of microfluidic devices with multiple integrated functional components.
Feng Li, Petr Smejkal, Niall P. Macdonald, Rosanne M Guijt, and Michael C. Breadmore Anal. Chem., Just Accepted Manuscript DOI: 10.1021/acs.analchem.7b00409 Publication Date (Web): March 21, 2017 Copyright © 2017 American Chemical Society