Modeling transport in paper microfluidics

Paper based microfluidic devices are extremely promising as an inexpensive and highly customizable platform for assays. Flow and particle transport in these highly porous and disordered materials are not well characterized, however, presenting a challenge for the construction of reliable devices that may require well-timed transport of cells and media such as blood. In this work, we identify design and material parameters crucial to transport, and experimentally characterize their influence through a sequence of test devices, where the fluid flow is tracked using our new open-source software package developed for this purpose. Measurements are compared with theoretical modeling to identify the physical processes and relevant timescales involved. Prospects for control and design of future devices will also be discussed.