Fabrication of Paper-based Device Using Printing Circuit Technology

This paper describes the use of a printing circuit technology to generate hydrophilic channels in a filter paper. Pattern was first designed using Protel soft, and printed on a blank paper. Then, the pattern was transferred on a sheet copper using a thermal transfer printer. The sheet copper with pattern was dipped in a ferric trichloride solution to etch the whole pattern of the sheet copper. At last, the etched sheet copper was coated with paraffin, then with a filter paper and heated at the other side of the sheet copper with an electric iron. The melting paraffin penetrated full thickness of the filter paper and formed a hydrophobic "wall". Colorimetric assays for the presence of protein and glucose were demonstrated in the paper-based device. The work is helpful for researching paper-based microfluidic devices for monitoring health and detecting disease.