When people talk about microfluidic devices and their potential applications, they always talk about the cheapness and portability of viral detection and delivery devices. There always is an undercurrent, though, of startups, price points, and giant companies being used for distribution and sales. This isn't necessarily a bad thing, but such an important and potentially life-saving technology doesn't need to be so tightly controlled by those with the biggest financial interests.

That's one reason it's so uplifting to find out about Diagnostics for All—a non-profit organization that is trying to bring lab-on-a-chip technologies to parts of the world that may not be able to afford it. The company uses a patterned paper platform for their diagnostic devices. From the site:

To fabricate a diagnostic device, DFA patterns channels and assay zones (or wells) of water-repellent materials into a piece of paper roughly the size of a postage stamp. Biological and chemical assay reagents are then deposited in the wells. When blood, urine, saliva, sweat or other biological samples are applied to the device, the paper wicks the sample through the channels to the assay zones, without external pumps or power. Upon contact, the assay zone quickly changes color and results are then easily read by comparing the color change with a reference scale printed on the device. After use, the device can be easily disposed of by burning. As we develop more advanced diagnostics, DFA's paper devices can be embedded with electrical circuitry to enable resistive heating, electrochemical assays, or initial processing of assay results.

And the reason this project—started in 2007 by Harvard's George Whitesides—is gaining attention now is because the company announced this week that it has just received a $100,000 Grand Challenges Explorations grant from the Bill & Melinda Gates Foundation. The grant is "designed to support a global health research project for the diagnosis of HIV in Third World countries."

Just the fact that this kind of hybrid biotech/non-profit company can exist and gain support from someone as influential and charitable as the Bill & Melinda Gates Foundation serves to remind the research community of the real importance of their work—saving lives.

When people talk about microfluidic devices and their potential applications, they always talk about the cheapness and portability of viral detection and delivery devices. There always is an undercurrent, though, of startups, price points, and giant companies being used for distribution and sales. This isn't necessarily a bad thing, but such an important and potentially life-saving technology doesn't need to be so tightly controlled by those with the biggest financial interests.

That's one reason it's so uplifting to find out about Diagnostics for All—a non-profit organization that is trying to bring lab-on-a-chip technologies to parts of the world that may not be able to afford it. The company uses a patterned paper platform for their diagnostic devices. From the site:

To fabricate a diagnostic device, DFA patterns channels and assay zones (or wells) of water-repellent materials into a piece of paper roughly the size of a postage stamp. Biological and chemical assay reagents are then deposited in the wells. When blood, urine, saliva, sweat or other biological samples are applied to the device, the paper wicks the sample through the channels to the assay zones, without external pumps or power. Upon contact, the assay zone quickly changes color and results are then easily read by comparing the color change with a reference scale printed on the device. After use, the device can be easily disposed of by burning. As we develop more advanced diagnostics, DFA's paper devices can be embedded with electrical circuitry to enable resistive heating, electrochemical assays, or initial processing of assay results.

And the reason this project—started in 2007 by Harvard's George Whitesides—is gaining attention now is because the company announced this week that it has just received a $100,000 Grand Challenges Explorations grant from the Bill & Melinda Gates Foundation. The grant is "designed to support a global health research project for the diagnosis of HIV in Third World countries."

Just the fact that this kind of hybrid biotech/non-profit company can exist and gain support from someone as influential and charitable as the Bill & Melinda Gates Foundation serves to remind the research community of the real importance of their work—saving lives.

Researchers race to bring cheap HIV testing to rural regions of developing countries.

This story originally appeared at Inside Science News Service, and is republished here with permission.

By Devin Powell, Inside Science News Service

This thin-section transmission electron micrograph (TEM) depicted the ultrastructural details of a number of "human immunodeficiency virus" (HIV) virus particles, or virions. Credit: CDC.gov | Cynthia Goldsmith Rights Information

PORTLAND, Ore. (ISNS) -- Most Africans infected with HIV live in rural areas, where access to HIV testing has lagged behind the growing availability of HIV-fighting drugs. Only clinics in big cities can afford the blood work equipment that allows doctors to monitor the disease's progression and treat it early and effectively. Doctors in rural areas often prescribe treatment based only on the visible symptoms their patients show. Responding to this need, researchers at California company Palo Alto Research Center have shrunk the laser technology inside large laboratory machines down to about the size of an iPod. Their cheap, handheld device promises to provide an immune system check-up on the spot and in less than 10 minutes. "You need a device that a health worker can put into a backpack to reach the people in Africa or Asia," said Peter Kiesel, who presented his team's battery-powered prototype at a recent meeting of the American Physical Society in Portland, Ore.

The technology analyzes a small sample of blood drawn by a finger prick. Blood cells flow through a tiny channel, illuminated by a laser beam. A detector watches patterns in the light that bounces off the cells to identify them.

The detector looks for and counts CD4+ T cells, cells in the immune system that are killed by the HIV virus. The World Health Organization recommends that antiretroviral treatment begin when a patient's CD4 count drops below 250.

"The quality of their test is great," said researcher Bernhard Weigl of PATH, a non-profit reviewing a variety of CD4 testing technologies. "If you look at their graph, it pretty much looked like the graph you would get from a big instrument."

PARC's prototype cost about $250 to build, a hundred times cheaper than the large flow cytometers currently in use. Still, getting it to market may prove challenging.

Kiesel is competing against a dozen other groups vying to fill the need for cheap, portable CD4 tests. Other technologies have been under development for years, including a half-dozen recent projects funded by the Bill and Melinda Gates Foundation that include disposable CD4 tester kits as easy to use as a home pregnancy test. Kiesler's laboratory-tested device is a couple of years behind these projects, some of which have been tested in the field in African countries.

None of these devices is currently on the market. Many have been redesigned several times in the quest for commercialization, including a device by the Austin-based biotech company LabNow, which had hoped to have its technology on the market by 2006.

In the end, Weigl suspects that health workers will use some combination of these approaches in the field. Detectors like the one at PARC, with a low cost per person tested, make sense for areas with many cases of HIV, said Weigl. But disposable kits, which cost less initially and require no maintenance, may be a good solution for remote areas with fewer cases.

"I would be surprised if the first technologies aren't out by 2012," said Weigl. "The market is big; you're looking at many millions of users that have to get checked up every few months."

Researchers at Harvard's SEAS have put together a new chip with some pretty fantastic measurement and detection capabilities.

The platform combines a high throughput microfluidic device with 62 high powered lenses to create a new kind of optical lab-on-a-chip device.

The researchers—including Dr. Crozier and Ethan Schonbrun a graduate student at SEAS—claim that the whole system has the sensitivity of a large microscope, describing it as a "massively parallel approach." On top of that, the device can test up to 200,000 drops per second... and Dr. Crozier hopes to be able to push that further.

The team is optimistic that the device could enhance microfluidic and lab-on-chip devices for use in applications such as in-the-field biological assays.

The work is described in full in Lab on a Chip (Issue 5, 2010).

Using lab-on-a-chip technology for DNA detection and analysis is one specific goal many researchers are inching toward. Researchers have now offered a way to align DNA strands to allow for analysis within a nanofluidic channel. The difficulty and cost of creating nanochannels is an impediment, but new research, published in Biomicrofluidics, offers the use a cost-effective material that could garner long term results in DNA analysis.

Nanochannels offer a way to align and analyze long biopolymer molecules such as DNA with high precision at potentially single basepair resolution. In the article "Complementary metal oxide semiconductor compatible fabrication and characterization of parylene-C covered nanofluidic channels with integrated nanoelectrodes," published today in Biomicrofluidics, Chih-kuan Tung, Robert Riehn, and Robert H. Austin, present a novel method of fabricating nanochannels with parylene, while measuring impedance characteristics with 25 nanometer thick electrodes. Parylene-C is a cheap and robust material, which is typically used for coating printed circuit boards as well as stents, defibrillators, pacemakers, and other implanted medical devices.

The researchers believe that this technology will open up opportunities for electronic detection of charged polymers, and that "with techniques to fabricate nanoelectrodes with nanochannels, it should be possible to include integrated electronics with nanofludics, allowing the electronic observation of a single DNA molecule at high spatial resolution."

Enough with these housekeeping details, how about that article on describing pizza tossing with nonlinear differential equations?

There's more microfluidics here than meets the eye... yes, of course we have to worry about how the sauce flows, but what Drs. Yeo and Friend have done here is use the physics of tossing dough to design SWUMS—standing wave ultrasonic motors. The motors are only about 250 µm wide and could travel through blood to take on dangerous bodily intruders one-on-one.

If you think these two have done enough research, you haven't been reading the New Scientist. In this NS online article, Dr. Yeo explains how his group has used surface acoustic waves to create a type of earthquake on a microchip. The earthquake converts the drug into an extremely fine mist that can then be absorbed quickly through the skin into the bloodstream. The research article appeared in Lab on a Chip.

Oh yeah, and there's this super cool video too:

Enough with these housekeeping details, how about that article on describing pizza tossing with nonlinear differential equations?

There's more microfluidics here than meets the eye... yes, of course we have to worry about how the sauce flows, but what Drs. Yeo and Friend have done here is use the physics of tossing dough to design SWUMS—standing wave ultrasonic motors. The motors are only about 250 µm wide and could travel through blood to take on dangerous bodily intruders one-on-one.

If you think these two have done enough research, you haven't been reading the New Scientist. In this NS online article, Dr. Yeo explains how his group has used surface acoustic waves to create a type of earthquake on a microchip. The earthquake converts the drug into an extremely fine mist that can then be absorbed quickly through the skin into the bloodstream. The research article appeared in Lab on a Chip.

Oh yeah, and there's this super cool video too:

In an earlier entry (Tiny Bubbles), I mentioned the idea of creating logical circuits by using nanoliter droplets through a microchannel. Microfluidics and circuits use similar terminology; notably "active" and "passive." An active electronic circuit draws power (usually for an operational amplifier) to shape a signal, whereas the passive circuit can be used without a power source. The advantages of the passive unit are low cost, zero power consumption, and long-term stability. Active components efficiently shape a signal, but at a cost of requiring a power supply.

Turning back to microfluidic devices; passive components have much the same advantages as passive circuitry: easy and cheap to fabricate and maintain, and more reliable and consistent performance. Because they're cheaper to produce, the possibility of a disposable lab-on-a-chip, or μTAS (Micro-Total Analysis Systems), device is more feasible.

More specifically, the passive microvalve has proven a valuable little invention. These valves can be as simple as a rubber flap (loosely speaking), but one chip could contain thousands. In addition to valves, passive versions of micropumps, -mixers, -dispensers, and -filters are used in increasingly complex microfluidic devices.

The important thing in science is not so much to obtain new facts as to discover new ways of thinking about them. —William Bragg

I think Bragg would be excited about these types of biomicrofluidic advances. Delving further into the circuit/microdevice analogy seems worthwhile, considering the wealth of devices that are based on complex arrangements of simple circuits. How will scientists stretch this comparison further?

Will these passive components be responsible for a future torrent of advancement in the field of disease detection in third world countries? I would imagine that they will and more. There'll be an increasing number of advances in micro- and nanomechanical sensors for environmental, chemical, and biological detection as well. In addition to giving scientists new avenues for detection, the device opens up all sorts of opportunities for epidemiologists to study how a certain strain of a disease moves through a population or how a chemical spill spreads throughout a region, for example.

Singapore scientists have developed the best lab on a chip yet—one that detects avian flu (H5N1) and gives results in under 30 minutes. At the heart of the chip is a new more efficient method of analyzing RNA, which will eventually lead to other quick tests such as those for HIV, SARS, and Hepatitis B.

Here, there are two fascinating stories rolled into one: the first is an epidemiological breakthrough and all of the implications it may have on predicting or preventing a future pandemic. Current technologies take about 5 hours to test for H5N1, and looks to be at least 40 times cheaper. And forget trying to lug that kind of medical equipment to a remote or harsh climate in southeast Asia .

The microfluidics that the device employs integrates the entire workflow of viral RNA isolation, purification, preconcentration, and detection. Dr. Juergen Pipper, one of the researchers, explains:

The novelty of our method lies in the way that the droplet itself becomes a pump, valve, mixer, solid-phase extractor and real-time thermocycler. Complex biochemical tasks can thus be processed in a fashion similar to that of a traditional biological laboratory on a miniature scale.

The complex microfluidic device will hopefully be in production in time to bring solace to countries where a SARS outbreak poses a threat.

Microphysical devices are also offering solace from your lackluster golf game. Check out Sonic Golf's nifty training tool, which emits a pleasant tone when your club is swung correctly and an high-pitched annoying one when you're about to hook a golf ball into the woods. The real usefulness comes from receiving feedback the instant your swing goes awry, so you'll know exactly which part of your golf stroke needs adjustment. The device contains microelectromechanical systems (MEMS) that measure your swing's velocity and acceleration. The feedback mechanism created by the golfer and the device is what the device's inventor (Robert Grober, a Harvard physics professor) seems to think this is the key to mastering your stroke.

It is, of course, debatable which direction of research humanity should be most concerned about; improving golf scores or preventing global pandemics. For now, we get to have both.