By Bouchra Ouatik
In modern hospitals, doctors rely on ever more sophisticated technologies to perform quick and accurate diagnostics. But chemist George M. Whitesides thinks we're headed the wrong way with high-tech medical devices. For global medicine, cheaper is better, Whitesides claimed on Feb. 20 at the 2011 AAAS meeting in Washington D.C.
“How do we deliver information useful in diagnostics and diseases in circumstances in which we have no money, no electricity, no refrigeration, no water, no doctors, and no understanding of diseases?” asked Whitesides. For the 71-year-old Harvard University chemist, the answer lies in developing “zero-cost” technologies, designed to be as simple as possible.
Whitesides' solution fits on a stamp-sized piece of paper. The scientist is known for his work on “labs-on-chips,” miniature devices made of inexpensive materials and designed to carry out the same kind of experiments as in a full-size lab, only at a much smaller scale.
His latest one, presented at the meeting, is made of ordinary paper. For the manufacturing process, the chemist drew his inspiration from comic books.
“Can we make comic books as diagnostics systems?” asked Whitesides. "The answer is yes.” Using a water-repelling ink, the printer draws a pattern of channels and wells, which serve to analyze fluids such as blood or urine. Once the paper is out of the printer, the lab is ready for work.
“You put a drop of urine on the paper,” said Whitesides, “and it wicks its way up and distributes itself in the channels.” For example, one spot of the paper is soaked with a chemical that turns blue in the presence of glucose, and another spot turns brown to indicate protein. “And this gives you a measure of liver function,” explained Whitesides.
This innovation requires no electricity. The fluid flows naturally, funnelled by the printed channels, while the color-changing chemicals provide information on the patient's health. And it costs only a few cents to make, Whitesides underlined.
“Paper is everywhere, you can stack it, and it's unbreakable,” he said. Further, these paper labs eliminate the need for syringes. The patient must be pricked with a needle to get a drop of blood out, but the needle can be immediately disposed of. Only the paper remains, solving the problem of biomedical waste disposal.
“To dispose of it, you just throw it in the fire,” said Whitesides.
The urine test is only one of the simplest examples of low-cost medical testing, Whitesides said. More complex systems can be made by stacking additional layers of paper and ink. These can test for a wide array of diseases such as HIV, malaria and hepatitis, all widespread in developing countries.
In remote areas with limited hospital access, the patient could use a cellphone camera to take a picture of the test and send it to a hospital for further diagnosis. With increased cellphone in developing countries, this system would make health monitoring more accessible worldwide.
For the Harvard professor, this is only the beginning of a radically new way to think about engineering.
"The usual way to do this in the U.S. is to take an existing device, make functions smaller and the cost will decrease,” Whitesides said. But the cost can only get so low with that approach, he noted: “Instead, we start with a technology that is as inexpensive as anything we could make and build value.”
As Whitesides summed up through the words of Albert Einstein: “Everything should be made as simple as possible, but not simpler.”
Bouchra Ouatik is completing a certificate in journalism at Université de Montréal, and holds a bachelor's degree in engineering physics from École Polytechnique de Montréal. She is currently an intern at the Canadian Broadcasting Corporation, for radio and television science programs. She also freelances for magazine Québec Science. Reach her at bouchra.ouatik@gmail.com.
