Microfluidics without pumps: reinventing the T-sensor and H-filter in paper networksElectronic supplementary information (ESI) available: Figures of experimental setup and serial dilutions. See DOI: 10.1039/c004812f

Conventional microfluidic devices typically require highly precise pumps or pneumatic control systems, which add considerable cost and the requirement for power. These restrictions have limited the adoption of microfluidic technologies for point-of-care applications. Paper networks provide an extremely low-cost and pumpless alternative to conventional microfluidic devices by generating fluid transport through capillarity. We revisit well-known microfluidic devices for hydrodynamic focusing, sized-based extraction of molecules from complex mixtures, micromixing, and dilution, and demonstrate that paper-based devices can replace their expensive conventional microfluidic counterparts. We demonstrate translation of well-known microfluidic devices for hydrodynamic focusing, sized-based extraction of molecules from complex mixtures, micromixing, and dilution onto low-cost paper-based devices.