Hollow-Channel\nPaper Analytical Devices

Abstract

We present a microfluidic paper analytical\ndevice (μPAD)\nthat relies on flow in hollow channels, rather than through a cellulose\nnetwork, to transport fluids. The flow rate in hollow channels is\n7 times higher than in regular paper channels and can be conveniently\ncontrolled from 0 to several mm/s by balancing capillary and pressure\nforces. More importantly, the pressure of a single drop of liquid\n(∼0.2 mbar) is sufficient to induce fast pressure-driven flow,\nmaking hollow channels suitable for point of care diagnostics. We\ndemonstrate their utility for simple colorimetric glucose and BSA\nassays in which the time for liquid transport is reduced by a factor\nof 4 compared to normal cellulose channels.