Driving flows in microfluidic paper-based analytical devices with a cholinium based poly(ionic liquid) hydrogel

Paper microfluidics technology requires effective handling and control of fluids, and this remains as a significant obstacle for their accessibility by end-users, inhibiting their transition from the laboratory into the market. Here, the synthesis, characterisation and performance as negative passive pumps of cholinium based poly(ionic liquid) hydrogels are presented, for the manipulation of fluid flow in microfluidic paper based analytical devices. The hydrogel was able to direct the fluid flow preferentially, and prevent fluid from flowing in other directions, thus opening possibilities for effective fluid flow manipulation in mu PADs. Moreover, the hydrogel 'passive pump' improves the water retention capacity of the mu PAD by a factor of nine when compared to the bare mu PAD. Furthermore, the operational lifetime of this PAD configuration was greatly increased by the integration of the hydrogel passive pumps. (C) 2018 Elsevier B.V. All rights reserved.