Fabrication of cost-effective and efficient paper-based device for viscosity measurement

Use of paper-based devices for affordable diagnostics is gaining interest due to unique advantages such as affordability, portability, easy disposability and inherent capillarity. As capillary transportation is an integral component of paper-based devices, low sample volume with faster measurement becomes an additional advantage. We have developed a simple, paper-based microfluidic device suitable for measuring the viscosity of Newtonian fluids as well as a few non-Newtonian fluids with sample volume as little as 12-20 mu L. The results could be obtained much faster than the conventional methods. A comparative analysis of the results obtained with our paper-based viscometer and with that of the conventional Ostwald viscometer shows a correlation coefficient greater than 0.99. Apart from viscosity measurement, the paper-based devices were tested for protein denaturation and polymer molecular weight determination. Our results show that the paper-based viscometer could be a potential alternative for the conventional viscometers in the viscosity range from 0.9 cP up till similar to 40 cP, with added benefits in terms of time, cost and low sample volume requirement. (C) 2018 Elsevier B.V. All rights reserved.