For decades, the electrical properties of human blood have been of interest in a wide range of biomedical applications, such as in radiofrequency hyperthermia, body composition, electrocardiography, and the diagnosis and treatment of various physiological conditions.

In a recent article published in Biomicrofluidics, researchers at King Abdulaziz University in Saudi Arabia have published a study of the electrical and mechanical (viscosity) properties of blood and the effects of electrical conduction on its microstructure. The authors use many parameters in their research and conclusions, including the relaxation time of micro-cells, molecules, bacteria, protein, hormones, glucose, chemicals, vitamins, and antibodies, which all greatly influence the chemical and physical character of blood.

A press release with further details will be released on AIP's EurekAlert page along with breaking news from all AIP publications.

One of the tastiest things I can think of is Jell-O—and just in time to celebrate the Second Annual Jell-O Mold Competition, comes a bit of research from the ACS journal, Analytical Chemistry.

The article, "Using Inexpensive Jell-O Chips for Hands-On Microfluidics Education¹," presents an interesting model of microfluidic devices using, you guessed it, Jell-O.

The idea is to get anyone (probably mostly Jell-O enthusiasts) really excited about microfluidics. Getting students to design and build a microfluidic device could spark an immense interest in a technology that could one day be as commonplace as cellphones.

This figure at right shows the authors' scheme for "producing Jell-O chips using soft lithography," whose hopes are they certain key concepts—including photolithography, crosslinking density, photopolymerization, and rapid prototyping—will be easily conveyed to students of all levels. The article runs through a few different chip designs, including one that demonstrates pressure-driven flow, another that teaches principles of dimensionless numbers, and finally a "Jell-O chip" that can be used for teaching the fundamentals of pH sensing and parallelization,

This isn't explicitly mentioned, but I'm hoping the authors take into account how hungry the students are before proceeding with additional lessons... at the end of the day, there might not be enough Jell-O to go around.

Nature Methods has been around for a few years now but I always sort of forget about them for some reason. Well, luckily I read what Google tells me to and not what my lousy memory tells me to.

So I was pleasantly surprised to read this feature story by Nature Method's technology editor, Nathan Blow. Dr. Blow presents a lovely and easy to read overview of what he calls "The great divide" between the intricate and sophisticated microfluidic devices that are created in laboratories and the small number of commercially available products.

The piece really speaks for itself and the community, so there's not much to add, except it's good to see that this great divide is narrowing a bit.

Ah, HeLa cells... everytime I see the name now I think of Rebecca Skloot's newly released book on the subject. The treatment of Henrietta Lacks was unfair at best... Anyone who reads Skloot's book has to agree that Lacks was wronged. It may not be any consolation, but her legacy has become life-giving and has borne many innovations. Here is yet another cool little bit of research that use the HeLa cell line.

This article—published last week online in Biomicrofluidics—details the use of a microfluidic device that is used to observe, in real time, the death of the HeLa cancer cells.The platform uses a stepwise concentration gradient of drugs.

The authors conclude that:

This microfluidic platform can provide several advantages:

1. Cytotoxicity of drugs at multiple concentrations can be simultaneously studied in parallel on one chip, thus saving time and labor and reducing systematic errors
2. The sample size can be largely reduced
3. Microfluidic chambers facilitate long-time tracking of individual cells, and
4. microscopic imaging can give higher optical sensitivity than fluorescent scanner or UV-visible absorption.

...This prototypic system should be useful in the areas of biology and bioengineering, especially for discovering apoptosis-inducing agents as potential anticancer drug candidates.

Biomicrofluidics was represented at the 2010 APS March Meeting in Portland, Oregon from March 14-18.

There were several interesting sessions related to the journal. Here are a few highlights: Alex Levine from UCLA talked about "Cell Quakes: Mechanics and Microrheology of Living Cells and Active Gels". Dennis Wirtz, John Hopkins University gave his overview of "Intracellular Fluid Dynamics.". Cindy Harnett from the University of Louisville presided over a session on Microfluidic Devices, where mechanical actuators—including propellers, paddles, and wheels—were discussed along with several other bio-related flow research. Richard Fair, Duke University, talking about "Electrowetting Control of Droplets for Biomedical Applications on Chips".

The days were filled with lots of interactions between students, APS and AIP editors, and researchers from all sorts of fields. What sorts of interesting stories or experiences did you have at APS this year? Anything "microfluidic?" "fabri-tastic?"

Finally, someone has figured out how to stop spilling tea all over the place! These fluid flow geniuses in France have published a treatise on the "teapot effect" in Physical Review Letters. The so-called "teapot effect" is "the annoying tendency for a liquid to trickle down the outside of a receptacle after pouring."

I, for one, am relieved and immensely impressed.

Apparently there are two big issues at hand; the first is flow separation. When a fluid starts moving more slowly it begins to separate from itself, making it more likely that it will spill onto your pantaloons. The second factor is the hydrophobicity of the teapot—or whatever vessel you are serving your liquid of choice in. Teapot makers have long tried to build the perfect spout by altering the physical shape and size, but what they should have been doing is using a highly hydrophobic material for construction.

I think this would be best represented by a teapot made of lotus leaves—in this way an homage is made to Chinese culture, who also happen to love tea and grow the lotus plant.

What's that you say? Making a teapot out of a leaf is absurd? Ok, ok, you win... we'll make the teapot out of butter... butter's hydrophobic, right?

Every time it rains,
I get microfluidics on the brain.

That's not entirely relevant to today's blog posting, but I thought it was true enough... plus, it rhymes, so, that's kind of neat.

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).

Imagine my delight when I searched YouTube for "microfluidics" and got 275 results. Go ahead, I'll wait while you conjure up a picture of me grinning madly...

Anyway, the field is obviously growing rapidly, but I was surprised to see that the multimedia is being dispersed across the web. I can't decide whether this video explosion is due to the field's popularity or whether young researchers are actually finding that YouTube is useful tool for dissemating their research. Granted, most of the comments are along the lines of "Cool!" or "Science is great," so it may just be that bored people are stumbling across some pretty pictures—don't get me wrong, though, that's fantastic.

Well, regardless, here are two interesting microfluidics videos:

This one actually contains a lot of great information, including formulas, although I wouldn't go so far as to call it self-contained. The user who posted this doesn't seem like a company or research group, so it's not really a promotion item, which I can appreciate. He's just a nice fellow who happens to do research that he's proud of so he put it on youtube. Better than posting a video of yourself lip-synching to AC/DC, right?

This one is a little different because of the C. Elegans. There's nothing better than watching an animal work its way through a maze. Here, the Wheeler Lab has posted their group's research. I can definitely appreciate the quality and content here. Great job!

To quote the impassioned Dr. Steve Brule, "...go make some computer technologies of your own! Get out of the house and go do it!"

Each of our bodies respond differently to stimuli. For example, I could go outside and lay down in a patch of Poison Ivy (Toxicodendron radicans) and be fine, but my mom will break out in grisly red bumps. A more apt example might be that I could take NyQuil for my cold, fall asleep and wake up rested, whereas a friend could take the same dose and lie awake in a restless state all night long.

The microfluidic chip above is manufactured by Fluidigm, and will be used to simultaneously perform more than 9,000 reactions to try and predict a patient's response to a particular treatment for prostate cancer. Credit: Fluidigm

There are genetic reasons some drugs produce different responses for different people. So, what's the solution? Test each patient's genes and run about 9,000 simultaneous reactions to analyze the differences in how a patient's genes are expressed, rather than the specific genetic structure. This is an important distinction—sequencing genetic code is not yet a good indication of what will ultimately be expressed. Expression is a complex system that relies on many many genes to decide what ultimately happens inside your body. So this is exactly what Howard Scher, chief of the Genitourinary Oncology Service at Memorial Sloan-Kettering Cancer Center, has proposed in a new clinical trial for prostate cancer. The trial will take a look at rare tumor cells and analyze them using a microfluidic chip—the results will allow the researchers to decide how well the patient will respond to a certain drug. Essentially, the researchers are "building a profile" for the patient's tumor, which they can then use to decide what the best treatment will be. The chip—manufactured by Fluidigm, a South San Francisco biotech company—uses only a few nanoliters of reagent, and is combined with DNA through a series of valves and channels. One chip costs about $300. Emily Singer wrote a lovely and concise article about the upcoming trial in MIT's Technology Review.

There is something oddly calming about dulcet and jazzy music mixed with microject visuals. Both move fluidly and calm the senses.

Ming K. Tan, James R. Friend, and Leslie Yeo reported in the July 10 Physical Review Letters a way to induce a fluid jet to burst from an isolated droplet. The method uses surface acoustic waves (SAWs) to excite the fluid. The amplitude of the SAWs are just a few nanometers and the frequency is 30 megahertz, creating the surface acceleration seen here and leading to eruptions that sent droplets 1 to 2 centimeters in the air.

This year's combined 13th International Conference on Surface and Colloid Science of the International Association of Colloid and Interface Scientists, and the 83rd Colloid and Surface Science Symposium was held at Columbia University in New York City. Now that I've gotten the giant name of this conference out of the way, I'd like to talk about some highlights.

This year's even drew over 1100 attendees—a good turnout in most of the attendees' opinions. Because Biomicrofluidics was sponsoring the "Electrokinetics & Microfluidics" sessions, here are a couple of highlights from that session:

Monday morning, Howard A. Stone began the session to a crowded room with his lecture on "Multiphase Flows in Confined Systems." Dr. Stone explored the idea of using microfluidic approaches in multiphase hydrodynamics in confined systems and cellular-scale hydrodynamics.

Other highlights from the day included a lecture on "Droplet Breakup in Flow-Focusing Geometries," by Carnegie Mellon's Shelley Anna—who was also the co-organizer of that morning's session. The other organizer—Leslie Yeo, Monash University and editor of Biomicrofluidics—spoke next about "Microfluidic Interfacial Destabilization and Atomization," in which he described a "10 nanometer earthquake wave" with an acceleration at the surface reaching 10⁷ g's. He spoke briefly about some of the future applications for the research, including drug delivery and encapsulation, chip-based spectrometry, and "soft" molecular printing.

Tuesday afternoon's session started off with the keynote lecture from Hseuh-Chia Chang, from Notre Dame and editor of Biomicrofluidics. Dr. Chang, entitled "AC Polarization of Nanocolloids and Their Impedance Signatures in Strong Electrolytes." Dr. Chang described a method for open-flow nanocolloid assays that had several advantages to traditional methods: fast (less than 1 minute), label-free, sensitive (down to picoMolar concentrations) to hybridization, selective (down to 3 base pairs), and portable.

The real highlight for the journal came on Tuesday evening, when several good friends of the journal gathered to discuss their own research and whatever else popped up over a glass of wine.

BMF dinner attendees (left to right): Zhengdong Cheng, Texas A&M University; Sumit Gangwal, North Carolina State University; Hseuh-Chia Chang, Notre Dame; Ehud Yariv, Technion-Israel Institute of Technology; Kevin Dorfman, University of Minnesota; Peng He, Texas A&M University; Ahmet Can Sabuncu, Old Dominion University; Leslie Yeo, Monash University; Guiren Wang, University of South Carolina;

There have been several notable events here at Biomicrofluidics in the past few months.

First up, congratulations are in order for Leslie Yeo, our newest editor. Dr. Yeo is at Monash University in Victoria, Australia, and he brings with him a lot of enthusiasm and great ideas for moving BMF forward. Take a look at Dr. Yeo's editorial for more info.

Speaking of new editorial members, the journal is also welcoming James Friend as an Associate Editor (both Drs. Friend and Yeo are part of the Micro/NanoPhysics Research Laboratory). Dr. Friend's appointment is especially newsworthy because he is helping the journal with its newest topical section: "Fabrication and Laboratory Methods." It is hoped that this section will provide a strong reference point for researchers interested in developing lab-on-a-chip or related technologies.

Another piece of good news: the first two issues of Volume 3 has published a great quantity of high quality articles from the 2009 Conference on Advances In Microfluidics and Nanofluidics, which was held at the Hong Kong University of Science & Technology last January. And in case it slipped your mind you can scroll down—or click here—to listen to and read several of the posters presented at that meeting. Thanks to the efforts of BMF's editors—Hsueh-Chia Chang and Leslie Yeo—Biomicrofluidics is publishing more high quality papers than ever before. Just try to stop yourself from reading "Electrowetting on a lotus leaf" or "Rapid on-chip genetic detection microfluidic platform for real world applications."

Finally, there have been a few changes to the website. There is now a gallery of all videos contained in published articles since the journal's inception. It may also interest those with a desire for updates that don't exceed 140 characters that AIP Publishing is now on Twitter. With each tweet, BMF has seen a notable increase in traffic.

Once again proving that the journal's content is amazing.

The prognosis, diagnosis, monitoring, or therapy of many diseases—melanoma, breast cancer, HIV detection, liver diseases—relies on the results of an ELISA (Enzyme-Linked Immuno Sorbent Assay) test. Typically, ELISA is time consuming and tedious and involves mixing, incubation, and washing, all carried out on a 96-well microtiter plate.

To spice up that musty old procedure, Hongyan He and his colleagues at The Ohio State University have built an integrated microfluidic device on a compact disk (CD), which automatically performs some of the more tedious tasks of ELISA. Each step of the ELISA procedure corresponds to a subtle yet precise change in the rotation speed of the CD, so that the centrifugal force of the fluid through the microfluidic channels is carefully controlled. Combined with microfluidic capillary forces, the flow sequence is accurately controlled for the different solutions involved in the ELISA process. Dr. He's paper—just published in the current issue of Biomicrofluidics¹—focuses on a microfluidic biochip that is used to detect a cytokine IFN-γ, and theoretically the device can be used for additional immunoassay applications.

Dr. He and his team have been using the CD technology as a basis for other applications for several years now, but the new CD-based ELISA design was just published online in Biomicrofluidics¹, and builds off of several years of CD-based microfluidic research by Dr. He's and Dr. James Lee's team at OSU.²

¹He, H., Yuan, Y., Wang, W., Chiou, N., Epstein, A., & Lee, L. (2009). Design and testing of a microfluidic biochip for cytokine enzyme-linked immunosorbent assay Biomicrofluidics, 3 (2) DOI: 10.1063/1.3116665

²Lai, S., Wang, S., Luo, J., Lee, L.J., Yang, S.-T., and, Madou, M.J. (2004). Design of a Compact Disk-like Microfluidic Platform for Enzyme-Linked Immunosorbent Assay Analytical Chemistry 76 (7), 1832-1837 DOI: 10.1021/ac0348322

Biomicrofluidics was lucky enough to be able to attend the first Advances in Microfluidics and Nanofluidics Conference at Hong Kong University, January 5-7, 2009.

Below are 15 posters that were part of the poster sessions, 5 of which include audio interviews with the poster's author.

(click image for full size)

"Instability and Thermal Behavior of Droplet in PDMS Membrane Electrowetting Studied by High Speed Camera and Thermal Imager"
Jiang-Tao Feng, Zi-Qian Wang, Ya-Pu Zhao
State Key Laboratory of Nonlinear Mechanics (LNM), Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China

download the audio interview (mp3)

(click image for full size)

"Hydro-electronic Voltage Generation based on Water-Filled SWCNT"

Quanzi Yuan, Ya-Pu Zhao

State Key Laboratory of Nonlinear Mechanics (LNM), Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China

download the audio interview (mp3)

"Shearing of Mesoscopic Liquids in a Narrow Gap"
Chan Chia-Ling
National Central University, Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China

download the audio interview (mp3)

Presented in Mandarin: "Shearing of Mesoscopic Liquids in a Narrow Gap"
Chan Chia-Ling
National Central University, Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China

download the audio interview (mp3)

(click image for full size)

"The One Dimensional Dynamics and Transport of DNA Molecules in a Quasi-Two-Dimensional Nanoslit"
Po-Keng Lin¹, Keng-hui Lin^1,2, Chi-Cheng Fu³, K-C Lee³, Pei-Kuen Wei², Woei-Wu Pai⁴, Pei-Hsi Tsao⁵, and Y.-L. Chen^1,2
1Institute of Physics, ²Research Center for Applied Sciences, and ³Institute of Atomic and Molecular Science, Academia Sinica, Taipei, Taiwan, People's Republic of China
⁴Center for Condensed Matter Sciences and ⁵Department of Physics, National Taiwan University Taipei, Taiwan, People's Republic of China

download the audio interview (mp3)

(click image for full size)

"Simulate Micro-Channel Flows with Super-Hydrophobic Surfaces Using an Atomistic-Continuum Hybrid Method"
Qiang Li and Guo-Wei He
Laboratory of Nonlinear Mechanics (LNM), Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China

download the audio interview (mp3)

Pills hold a special place in the sci-fi fan's heart. In fact, it's a cliché that even a casual sci-fi fan would recognize: swallow a pill and have all of your worries and what ails you cured in an instant. In most sci-fi tales, though, there is an sinister underlying reason why the pill is such a huge success—mind control, for example.

So now Philips has developed a neat little pill with a microprocessor, battery, pH sensor, temperature sensor, RF wireless transceiver, fluid pump and—oh yeah, don't forget—the actual drug. I am subtly reassured by their site's description of the pill that this device will not control your mind or attempt any other sort of subterfuge.

This cute little guy is 11x 26mm and is called the iPill.

From the Philips site:

Digestive tract disorders such as Crohn's disease, colitis and colon cancer are becoming increasingly common, particularly in the western world. Crohn's disease and colitis can be treated with drugs, notably steroids, but many of these drugs have adverse and unpleasant side effects for patients when administered systemically as whole-body doses. However, by delivering the required drugs directly to the site of disease, dose levels may be lowered and many of these side effects could be reduced.

So the theory is targeted delivery of the drug is the most effective approach. This type of treatment, if perfected, would be wildly effective in treating small, hard to reach tumors, for example. This pill is limited to traveling within the intestinal tract, although it's not hard to imagine a similar device 100 times smaller that would navigate through blood vessels.

Once this kind of "pill" gets small enough, concerns begin to arise: one is the microfluidic behavior at these small scales. A doctor may be able to traverse the small intestine with a pea-sized pill, but what about driving a micro-car through blood-filled arteries? Also, our bodies' health might one day be controlled by a multitude of iPills. In that case, who would be best to navigate these tricky transports? A possible solution: hire video-game playing teenagers who've mastered the "microfluidic game play."

it's a trying world down there in the nucleus (unless you're mitochondrial DNA--they live on easy street). DNA isn't having an emotional day. It's just our old friend Brownian motion--he never stops moving in a fluctuating random dance. Also, Brownian motion might be a girl, no one knows for sure.

Well, Adam E. Cohen decided to do something about it. Yes, researchers have had some success in countering that infernal microscopic jiggle, but Dr. Cohen and his colleagues at Harvard been trying to look closely at the dynamics of DNA trapped inside of a microfluidic channel.

At the Industrial Physics Forum (part of the AVS annual meeting) in Boston last Monday, Dr. Cohen presented a lecture entitled "Single Molecule Imaging, Anti-Brownian Electrokinetic Trap."

Cohen is working with William E. Moerner at Stanford to discover the shape of a DNA molecule, how it deviates from an average shape, and the dynamics of how it moves from shape to shape. The results look very similar to different energy levels of electron orbits. I think. Maybe. Don't quote me on that. To see the pretty pictures yourself, take a look at this article published in PNAS last year.

Biomicrofluidics is sponsoring the 2009 Conference on Advances in Microfluidics and Nanofluidics in Hong Kong on January 5-7, 2009.

The first annual conference is an international and interdisciplinary conference with special focus on research activities in the Pacific Rim. It will be held at the beautiful campus of HKUST by the bay.

The objective of the conference is to provide a forum for researchers in this interdisciplinary subject area to disseminate recent theoretical/methodological developments and technological applications as well as a platform for fostering closer networks and collaborative ties. It is anticipated that this inaugural conference will be the first of a series or regular conferences along this theme.

The organizing committee is therefore inviting submissions of abstracts falling within the broad scope of micro/nanofluidic science and engineering. Authors of selected abstracts will be invited to submit a full contribution of their work for review and publication in one of two special issues of Biomicrofluidics.

The last decade has seen exponential growths in microfluidic and nanofluidic research in Asia, driven by robust funding with expectation that it will spur a large Asian biotechnology industry.

The intent of this conference is to bring researchers of different disciplines and nationalities together, which is necessary for the Asian community to advance to the next level. It is also an opportunity to expose Asian research achievements to leaders in the field and for Asian students to interact with them. Biomicrofluidics, an American Institute of Physics journal, will be the affiliated journal to facilitate the missions of this conference, and subsequent follow-up conferences.

The invited speakers are leading microfluidics and nanofluidics researchers in Physics, Chemistry and the various engineering disciplines. It is the hope of the organization committee that this will be the first of a regular Pacific Rim conference on the topics.

We cordialy invite you to join the conference and look forward to see you in Hong Kong from January 5th to 7th, 2009.

Have you ever found yourself staring into a half-filled cup of water at a straw--wondering what kind of kooky laws light obeys that can result in this shattered view? Maybe not, but I bet Xiquan Cui and colleagues at Caltech have.

In their most recent article, published an article in the Proceedings of the National Academy of Sciences (PNAS), they image Caenorhabditis elegans (a nematode) without using lenses.

The image here (click for larger version) demonstrates pretty amazingly that this novel imaging technique outshines an optical microscope. Besides, the tiny fluid based magnifiers are much cheaper and don't rely on any kind of "miniaturization" technique. Within microfluidics, it's usually a good idea to start small and stay small.

The authors claim that this new technology—dubbed "optofluidic microscopy"—"can significantly address a range of biomedical and bioscience needs and engender new microscope applications." That actually sounds a bit modest on their part. I might go so far as to suggest they've contributed significantly to microfluidics.

X. Cui, L. M. Lee, X. Heng, W. Zhong, P. W. Sternberg, D. Psaltis, C. Yang (2008). Lensless high-resolution on-chip optofluidic microscopes for Caenorhabditis elegans and cell imaging Proceedings of the National Academy of Sciences, 105 (31), 10670-10675 DOI: 10.1073/pnas.0804612105

How effective are videos and other multimedia in research articles? The most obvious benefit lies in experimental work. It may be easier to show rather than tell how an experiment is done. The best example of this is at the Journal of Visualized Experiments (JOVE), where a procedural video essentially is the peer-reviewed article. The benefits to researchers is immediate and potentially immensely helpful—but only if the videos are completely and wholly transparent and valid. That begs the question: when a reviewer "peer reviews" a video, does he or she reproduce the procedure to verify its veracity? Is this beyond the call of duty for a reviewer? Note: I'm not suggesting that any of these videos are flawed. To the contrary, they look incredibly pertinent and accurate.

Like many other journals, BMF offers the chance to publish video as well. A link to the video (mpeg, wmv, or avi) is embedded in the PDF as well as on the abstract page. This article offers a three videos of data, not of a procedure. Regardless, it's encouraging to see researchers taking advantage of multimedia capabilities. This article comes to BMF from National Taiwan University.

AIP is pretty excited about having more and more Chinese contributors to their journals. In fact, it looks as though Biomicrofluidics and its editors will be supporting and promoting a few upcoming meetings in China. There is a conference in Hong Kong January 5-9 2009: Advances in Microfluidics and Nanofluidics. "It should be the best Asian conference on Microfluidics and Nanofluidics," according to BMF's editor, Hsueh-Chia Chang. The conference website in now up and you can find the full speaker list and other helpful info there.