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:

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

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)

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."

The growing interest in DEP was evident at the recent 2009 Conference on Advances in Microfluidics and Nanofluidics in Hong Kong (Jan. 5-7). In fact, the editor of Biomicrofluidics was ecstatic, commenting, "We are in DEP heaven!"

A noteworthy work by Daniel Ou-Yang's group at the Physics department of Lehigh measures the DEP mobility of nanocolloids with an optical tweezers technique, as seen in his invited article in BMF¹. Note that he measures not just the cross-over but the mobility as a function of frequency. You will note in his last two figures the anomalous scalings that defy the Clausius-Mossotti theory.

Other notables right now include Elaine Zhu and Jiang Zhao who are working on molecular DEP—AC induced dipolar effects on polyelectrolyte conformation and hybridization with fluorescence correlation spectroscopy (FCS) techniques. Elaine just published a paper with Peter Hoffmann and Prasad Sarangapani in Langmuir² on binary nanocolloid phase separation by DEP and with Victoria Froude in an upcoming J. Phys. Chem. paper on DEP of liposomes. There are beautiful images and a very good characterization of surface conductance effect in Victoria's paper!

Another notable DEP paper is one on how DNA hybridization of nanocolloids changes their cross-over, by Zachary Gagnon and Senapati³, and was fast-tracked and featured on the cover of the December issue of Electrophoresis.

Open access is free, immediate, permanent, full-text, online access, for any user, web-wide, to digital scientific and scholarly material, primarily research articles published in peer-reviewed journals. OA means that any individual user, anywhere, who has access to the Internet, may link, read, download, store, print-off, use, and data-mine the digital content of that article. An OA article usually has limited copyright and licensing restrictions.

Visiting Raleigh was pretty neat, but it is very different from New York—the city is spread out. My hotel was downtown and the meeting was at the North Carolina State University campus. I arrived on a Sunday and after glancing at a map, though it would be a scenic walk to the campus. Well, it was kind of scenic, but the 95° heat completely negated any pleasure I potentially could have had from my midday saunter. Regardless, I had an excellent week and got to give away a bunch of USB drives branded with my favorite journal's web address (fyi: it's bmf.aip.org). If you were one of the lucky few that nabbed one, congratulations.

The non-meeting highlight was the reception on Tuesday evening—held in the small but nifty North Carolina Museum of Art. After wandering around taking a few pictures and stuffing my face with top-quality cuisine, I had a chance to talk to several post-docs and graduate students who seemed to be doing the same (who can blame them... you can't beat free food). Check out a few pictures from the meeting.

Anyway, keep an eye out for the upcoming special issue.

Dr. Chad Orzel, a physics professor and blogger on ScienceBlogs.com, recently posted an interesting post, Dorky Poll: Non-Abelian Sciences, wherein Orzel pondered the difference between physical chemistry and chemical physics. Of course the standard reply: "If you publish in the Journal of Chemical Physics JCP) you are a chemical physicist, and if you publish in the Journal of Physical Chemistry (JPC) you are a physical chemist" was promptly added to the comment section. But it reminded me that a couple of months ago, I had the pleasure of meeting a few of the editors of JCP, and they assured me that there is something much more distinct about their journal and its authors: rigor.

The word strikes me as one that is only used by those meticulous enough to know exactly what it means. That is a bit of a circular—and maybe a nebulous—argument, but it became clearer to me once I took a look at a few articles.

This article¹, published in JCP in April, takes a look at so-called nanodimer motors. There have been several synthetic molecular motors fabricated with nanoscale dimensions before, and Tao and Kapral discuss a chemical-reaction fueled method of propelling them. They propose that instead of only resulting in enhanced diffusion, the motors can instead be used in targeted dynamics and to perform tasks.

I bring it to the attention of the blog because of the theoretical rigor included in the paper—it's striking how mathematically thorough the paper is. Once again reminding me of what is perhaps the real difference between chemical physicists and physical chemists (no offense to my chemist friends).

Lots of neat-o scientific discoveries were stumbled on by two or more people at about the same time. Sir Isaac Newton and Gottfried Wilhelm Leibniz both invented calculus. The first patent for an integrated circuit was given to Robert Noyce while Jack Kilby's application was still being mulled over by patent clerks. Check out how the solution for the cubic equation came about—it was really more confusion than mutual discovery, but an interesting read nonetheless.

And, just over 30 years ago, Frederick Sanger published a pretty nifty paper on sequencing DNA. Sanger presented his "inhibitor method" to the world in the December, 1977 issue of the Proceedings of the National Academy of Sciences. Apparently, though, he was a few months too late, because Allan Maxam and Walter Gilbert had already published their paper: "A new method for sequencing DNA", in a February issue of PNAS. In the end though, Gilbert and Sanger shared half of the Nobel Prize (Paul Berg got the other half all to himself) in 1980. It seems though that Sanger really made out like a bandit, because the new sequencing method became known as the "Sanger" method and the Wellcome Trust opened the Sanger Institute. My question: where's the Gilbert Institute? The lesson: always publish second. Ok, that doesn't make sense. Maybe the lesson here is really: don't take advice from bloggers.

Oh well. I only bring it up because I just read this article on sequencing: H. Esfandyarpour and friends have published (in my favorite online open-access journal Biomicrofluidics) a description of a novel method for sequencing based on the heat created by the chemical reactions of DNA synthesis¹. Dubbed "thermosequencing," the authors like to think it may replace the Sanger method.

I can't claim to be an expert in sequencing, so I may come across as a bit naïve in my interpretation of the article. That being said, this seems like an amazing advancement. The temperature differences being measured here are only a few thousandths of a degree (~1500 µK). Cool. (My apologies for the lame pun, but honestly, how could I resist?) This kind of "temperature-based" approach to DNA sequencing strikes me as uncannily original. So, yeah, cool.

1. Esfandyarpour, H., Zheng, B., Pease, R.F., Davis, R.W. (2008). Structural optimization for heat detection of DNA thermosequencing platform using finite element analysis. Biomicrofluidics, 2(2), 024102. DOI: 10.1063/1.2901138]]> http://blogs.aip.org/biomicrofluidics/2008/05/heatbased-dna-sequencing-and-d.html http://blogs.aip.org/biomicrofluidics/2008/05/heatbased-dna-sequencing-and-d.html Allan Maxam calculus DNA sequencing integrated circuit Kilby Leibniz Newton Nobel Prize Noyce nucleic acids Sanger Sanger Method thermosequencing Walter Gilbert Mon, 12 May 2008 13:04:12 -0500