“The diagnostic tests designed in Dr. Whitesides’s Harvard University chemistry laboratory fit on a postage stamp and cost less than a penny. His secret? Paper.”
I’d read about this before. But glad to see that things are moving along well – funding, products, future. While diagnostics on paper is nothing new (pregnancy and diabetes test, those ubiquitous dip sticks), the creation of channels with wax allows for a more sophisticated chemistry.
This is a great example of lo-tech hi-tech, using simple, long-established tools to do something better. I think folks too often head for the more complex and more expensive because it’s easier and less constrained (I used to say the same thing about dumbphones vs smartphones).
What they’ve done here is printed out wax channels, added some chemicals (by hand!), cut and package the postage stamps. To use it, spot some liquid, the paper wicks the liquid through the channels, chemistry is done, and you read out the color.