| abstract |
Microfluidic devices are provided for continuous sampling of biological fluid for extended periods of time, e.g. for periods of time up to and including 10 days. The microfluidic devices can be made from porous hydrophilic substrate, e.g. hydrophilic paper substrates. The devices can include a collection pad, an evaporative pump, and a channel connecting the collection pad and the evaporative pump. Hydrogels at the collection pad can promote collection of sweat or other biological fluids from a subject, which in some aspects is assisted by the use of one or more microneedles on the substrate. An evaporative pump can provide for long periods of sampling by providing continual pumping, e.g. through the use of an evaporation pad where sampled fluid can evaporate. |