Abstract

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 μPADs. Moreover, the hydrogel ‘passive pump’ improves the water retention capacity of the μPAD by a factor of nine when compared to the bare μPAD. Furthermore, the operational lifetime of this μPAD configuration was greatly increased by the integration of hydrogel passive pumps.