Lab-on-a-Chip Made of Paper

Researchers at Harvard's Whitesides Research Group may have found a way to make microfluidics technology much cheaper by taking advantage of the natural movement of liquid through paper. Hopefully, their work will lead to the creation of disposable diagnostic tests, which will be simple and abundant enough for use in the developing world.

Albert Folch
(Credit: University
of Washington)

Microfluidics deals with the manipulation of liquid and one of its most promising applications is a lab-on-a-chip, which can work with much smaller fluid samples than larger devices. Existing microfluidic chips are generally made from relatively expensive materials like silicon, glass, or plastic, and have tiny pumps and valves that can be difficult to manufacture. George Whitesides and his team at Harvard have recently built a microfluidic device on a square of paper the size of a pinky fingernail. This device is the first example of paper microfluidics and is considered to be clever because paper is universally available.

Larger paper tests, like pregnancy tests, are common, but shrinking the paper and minimizing the quantity of required chemical reagents helps to reduce costs. Directing the sample to particular regions enables simultaneous performance of several tests. It also means that fluid samples can be much smaller, eliminating the need for syringes in developing countries.

The paper's natural network of capillaries is used to channel the liquid to the wells at the branches of the paper, allowing for multiple tests to be conducted simultaneously. However, the paper's limited pumping action will probably keep it from performing more complex chemical reactions in the near future.

Prototype of the new
paper lab-on-a-chip
(Credit: Andres W. Martinez)

In addition to being cheaper, these devices are light weight, disposable, and resistant to breakage, making them more portable and practical in the developing world. In an attempt to minimize the level of expertise needed to use the tests, the team plans to combine the paper tests with a system of cell phones for off-site diagnosis. The team envisions that in rural areas where doctors are limited, people who are trained only to conduct the tests carry them out "and send them back to a central facility where a doctor looks at that information and (recommends) diagnosis and treatment without having to actually be there," says Whitesides.

The next step is clinical trials and deployment in Africa, although the team is currently still testing the device under harsh conditions such as extreme heat, humidity, and pressure. The test units do not seem to be adversely affected. The team hopes to move beyond humans and develop tests for water, livestock, and other food sources.

TFOT recently covered several lab-on-a-chip devices. These chips include the "lab on a chip" for detecting oral cancer cells, developed at Texas University, and the Nanocytometer, which locates cancer cells or other specific cells in the blood, developed at the University of California, Berkeley.

More on the paper microfluidics technology can be found on MIT's Technology-Review website.

I say, hopefully, disposable tests will be simple and abundant enough for use in American homes so we can self-diagnose and self-medicate and chop out ultra-expensive doctors and laboratories from our health care budgets.

I regret to inform you that a person's medical history will still make the diagnosis about 90% of the time. An assortment of lab and imaging tests will confirm it. You'll need a doc to monitor adverse drug reactions. The more that is learned, the more new questions that you have.

> ... and chop out ultra-expensive doctors and laboratories from our health care budgets ...

The doctors, laboratories and hospitals are not atually the cost drivers. It is lawyers, litigation and insurance that make health care expensive. My daughter’s pediatrician has a plaque posted in the waiting room of his office. That says “DPT innoculation: vaccine $2.85 + insurance $87.50 + doctor’s fee $5 = $95.35”

Yes, you still just pay just the $10 co-pay at the office, but you are still paying for everything via your health insurance rates.

neverdem - I strongly disagree - you are plotting a trajectory of health costs that will at some point in the future consume all human production and savings - you are suggesting that current health costs cannot go down if the current level of human health is to be maintained - you are suggesting that advances in human health can only come about if more money is committed to health treatment - that is not the historical experience in areas of the economy that are exposed to financial transparency and competition - in the last century, in the USA, the cost of food, textiles, energy, and telecommunication have come down dramatically - economic sectors that see cost increases, like housing, rise only because consumers demand more space, higher quality, and more luxury - in the USA, I believe health costs are now above 16% of GDP - yet, half of all doctor visits result in no quantifiable improvement in the patient's condition - more than 25% of USA health care is committed to patients in the last year of life - perverse outcomes like this exist only because most USA health consumers do not see or feel the true costs of their treatments - if, or when, health care consumers do see the true costs, they will demand less expensive options and better outcomes, and American entrepreneurs will leap to provide the solutions - yes, health care is unlike most commercial business in that some treatments must be highly customized, some treatments carry high risk, and surgery cannot be done at home - yes, failing to treat, because a health consumer may not have money, will always be morally unacceptable - but, the home based, self-treatment ideal I described in my first post would be largely obtainable for motivated health consumers in a free market health economy - a comprehensive health history can be easily maintained on the web - in the near future, software programs could easily ask me follow up questions and prescribe medication, and could warn and educate me about outcomes and side effects - whew, sorry, long, long winded exposition - bottom line for me, I refuse to accept the idea that most Americans need their health care directed by, and monitored by, legions of highly paid professionals with six to twelve years of post graduate training - in closing, thanks for your daily science and technology posts - when I see the name “neverdem,” I always click

Thanks for the compliment, but I'm not sure where to start.

Survey: 60% Of Primary Care Physicians Would Choose Another Field

We have to import nurses from overseas. Medical knowledge increases only at the margins. We don't know what we don't know. a comprehensive health history can be easily maintained on the web could be very problematic with respect to employment, insurance and exploitation by bad guys. You can't take human nature and ignorance out of medicine. You also have to figure in government mandates and lawyers.

Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.