Parametric Analysis of Wax Printing Technique for fabricating Microfluidic Paper Based Analytic Devices (μPADs)

Abstract

This study focuses on the detailed parametric analysis of wax printing technique for producing a paper‐based microfluidic analytical device. The study of the important parameters for wax printing technique has been experimentally carried out. The simple process includes printing a pattern using wax based printer and melting the desired paper within the paper network producing a hydrophobic and hydrophilic network. The produced network confines the flow of fluid to the desired detection zones. A generalized model accounting for the spreading of molten wax within the porous paper material is derived and results obtained are compared experimentally and with the previously used Washburn’s equation. The deviation of the Washburn’s equation is due to the several assumptions made during the wax spreading in the paper. Most importantly, the derived analytical model is well validated by these experiments. The developed model shows improved results of the actual wax spreading and sufficiently gives the final width of the hydrophobic barrier accounting for varying printing widths, different working temperatures and time required for spreading of the molten wax within the paper network.