Manipulation of fluid flow direction in microfluidic paper-based analytical devices with an ionogel negative passive pump

Abstract

Microfluidic paper-based analytical devices (μPADs) are a relatively new group of analytical tools that represent an innovative low-cost platform technology for fluid handling and analysis. Nonetheless, μPADs lack in the effective handling and controlling of fluids, which leads to a main drawback for their reproducibility in large volumes during manufacturing, their transition from the laboratory into the market and thus accessibility by end-users. Herein we investigate the applicability of ionogel materials based on a poly(N-isopropylacrylamide) gel with the 1-ethyl-3-methylimidazolium ethyl sulfate ionic liquid as fluid flow manipulator in μPADs using the ionogel as a negative passive pump to control the flow direction in the device. A big challenge undertook by this contribution is the integration of the ionogel materials into the μPADs. Finally, the characterisation and the performance of the ionogel as a negative passive pump is demonstrated.