LAUSR

Abstract Distance-based paper microfluidics have been widely used in environmental and biomedical analysis due to simplicity, speed, low cost and suitability for unprivileged regions with untrained personnel. The fluid behavior in the paper microfluidics is controlled by the surface tension, the temperature, the contact angle, the viscosity of the fluid, the average pore radius of the paper, and the channel width. This review discusses the principle and the applications of distance-based paper microfluidics with emphasis on the different detection reactions. The review also summarizes the techniques used in paper microfluidics manufacturing and advantages/disadvantages of each technique. Sections about reagents-free paper microfluidics and their biomedical applications are also presented. The most challenging technical problems associated with the utilization of distance-based paper microfluidics have been discussed with proposed solutions. The review covers the state-of-the-art applications of distance-based paper microfluidics and the future trends in this area.