Tunable-delay shunts for paper microfluidic devices.
We demonstrate a novel method for controlling fluid flow in paper-based devices. The method delays fluid progress through a porous channel by diverting fluid into an absorbent pad-based shunt placed into contact with the channel. Parameters to control the delay include the length and the thickness of the shunt. Using this method, reproducible delays ranging from 3 to 20 min were achieved. A simple electrical circuit model was presented and used to predict the delays in a system. Results from the model showed good agreement with experimental observations. Finally, the shunts were used for the sequential delivery of fluids to a detection zone in a point-of-care compatible folding card device using biochemical reagents for the amplified detection of the malaria protein PfHRP2.
Department of Bioengineering, University of Washington , Seattle, Washington 98195, United States.
Bhushan J
BJ
Toley
Brittney
B
McKenzie
Tinny
T
Liang
Joshua R
JR
Buser
Paul
P
Yager
Elain
E
Fu
D003101:Collodion / Q000737:chemistry*; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation / Q000379:methods*; D010209:Paper; D013997:Time Factors
D003101:Collodion