Programming paper networks for point of care diagnostics
Shivani Dharmaraja, Lisa K. Lafleur, Samantha A. Byrnes, Peter C. Kauffman, Joshua R. Buser, Bhushan J. Toley, Elain S. Fu, Paul Yager, Barry R. Lutz · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 2013
Lateral flow tests (LFTs) are well-suited for rapid point-of-care testing in low resource settings. The wicking action of the paper strip moves the sample and reagents through the device without a need for pumps, but LFTs are typically limited to tests that can be carried out in a single fluidic step. The materials from LFTs can be reconfigured to create paper networks that automatically carry out multi-step fluidic operations, while retaining the same easy-to-use format as a conventional LFT. Here, we describe basic principles of wicking and system-level behavior of paper networks by analogy to electrical circuits. We describe key design principles for a previously-developed 2D paper network (2DPN) and introduce an alternative linear paper network (Pseudo-1DPN) that takes advantage of system-level behavior to perform clean sequential fluid delivery while reducing device running time.