Paper-based non-mechanical valves for autonomous multi-reagent lateral flow microfluidic devices

In this paper we report the first three-dimensional (3D) and non-mechanical valve as a building block to create paper-based autonomous microfluidic devices. The valve consists of two layers of porous media that regulate flow direction. The valve also enables one fluid to gate another. By combining a single valve with 3D microchannels printed on paper, we create a paper-based autonomous device to conduct an enzyme-linked immunoassay. Furthermore, we explore new device architectures to autonomously manipulate multiple fluids by incorporating additional valves in a device.