We were inspired by microfluidic cells (MF), and a recent article stating that paper could be used as a medium. Based on the overcrowding and poor access to healthcare in many 3rd world countries, we wanted to extend access to healthcare to overworked and understaffed/underfunded hospitals.
What it does
Our prototype can mix two prototyped 'reagents' (food dye), and move liquid without the use of pumps, purely by capillary action. We can also move liquid over and under branches of the previous layer, allowing compact creation of MF circuits, and have the capability to close one-time valves to better control the flow and storage of reagents. We read the reagent outcomes colourimetrically by use of a webcam and OpenCV, (a computer vision library).
How we built it
We used ~100 coffee filters, crayons, a heat gun, and tape to make portions of the coffee filter hydrophobic, and prevented leakage and directed the flow. We used scotch tape to separate layers of the filter paper, and selectively allowed points to carry fluid over or under other branches.
Challenges we ran into
We had some difficulty initially with the OpenCV library, and had some spillage of food dye while choosing an appropriate hydrophobic compound.
Accomplishments that we're proud of
We've successfully demonstrated that paper microfluidics is a possible cheap and realistically buildable alternative to classic microfluidics. (Especially in 3rd world situations)
What we learned
Always put plastic under a surface you use food dye on!
What's next for Paper-based microfluidic point-of-care diagnostics
We would like to next integrate the color-changing reagents with the camera to read a colourimetry assay as a bar code, and populate a patient's chart with the results of their test, automatically.