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Harvard’s George M. Whitesides has the highest Hirsch index of any living chemist, which makes him arguably the most significant in the world. The Hirsch or h-index is a kind of weighted score based on a numerical analysis of a scientist’s published work which factors in both the number of papers and the number of citations those papers receive by other authors.

Back in October of 2008, Whitesides, et. al. published a paper in the Royal Society of Chemistry’s journal Lab on a Chip that describes a technique for separating blood plasma for use in various immunoassays using a piece of plastic tubing taped to an eggbeater. The method can replace a $400 bench centrifuge for many purposes.

Sean Michael Ragan

I am descended from 5,000 generations of tool-using primates. Also, I went to college and stuff. I write for MAKE, serve as Technical Editor for MAKE magazine, and develop original DIY content for Make: Projects.


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Comments

  1. Rallen says:

    That’s the sound of centrifuge manufacturers crying.

  2. Big Daddy Dave says:

    I’ve seen researchers in Africa using similar hand cranks centi’s.

    I think the one I saw was part of a Schroeder Hand Drill

  3. dosher says:

    I have the great privilege of working for a company started by Dr. Whitesides, and have even been able to sit across the table from him at a company dinner. He is a very intelligent, kind man who had truly revolutionized many facets of biotech, nanotech, and chemistry. Related to the above post, I think, is his work in micro-fluidics. Micro-fluidics, for those unaware, is an approach to lab-on-a-chip technologies for making hand-held, cheap, easy-to-use diagnostic tests with no electric motors, pumps, or expensive machinery like centrifuges and UV spectrometers. They operate using capillary action in some cases; in others, compressed air provides the drive. A simple color change or other indicator provides a binary response, a yes/no answer to the question “Am I infected with…?” or “Is my liver healthy?” Dr. Whitesides and several business partners have formed a non-profit organization called Diagnostics for All (dfadx.org) whose aim is to create paper-based micro-fluidic diagnostics for the developing world. It is very simple innovations like an eggbeater centrifuge which makes health care possible for those who cannot even afford food. Invention and imagination are what science – and this website! – is all about.

  4. alandove says:

    This is a cool improvisation, though as Dave points out above there are similar designs already in use. It’s not much of a threat to centrifuge manufacturers, unless Whitesides et al. have figured out how to generate 100,000g forces with it, but for low-speed procedures like plasma separation, it’s perfect.

    To do useful diagnostic tests, you need some other components, of course, and that’s where the microfluidic devices come in. Whitesides is one of many researchers working on those. Most of the companies making these “lab on a chip” systems are modifying techniques from the semiconductor industry, which means you need a six-figure investment in lithographic equipment to play. However, there’s a way to make them in your kitchen. Google “Michelle Khine UC Irvine” for the details. The short version is that you print whatever microfluidic device you like onto Shrinky-Dink plastic, then shrink it in your oven, and you get a usable lab chip.

    Note to Make editors: Michelle’s work would be a great topic for the magazine.

    1. Colecoman1982 says:

      I’ve read about Michelle Khine’s work in the past (I think it was posted to Slashdot). It’s interesting, but not quite as DIY as it was presented by the article titles. My understanding of her process was that she was using the shrinky-dink material as a cheap lithography mask for when she etched the pattern onto more traditional materials (silicon, I’m assuming). Unfortunately, while the shrink dink part can be done by anyone with a printer and an oven, my understanding was that the actual etching process still required some specialized machinery. The major point of her work, if I remember correctly, was that it allowed her to accomplish much more by stretching her, extremely limited, resources/budget much further.

      1. alandove says:

        I interviewed her for an article I wrote for Nature Medicine. While she does use additional equipment in her lab, the technique could easily be modified for simpler tools and materials. She’s usually using the Shrinky Dinks as a positive mold, because printed lines on them bump up during the shrinking process. She then casts the actual microfluidic device in plastic against the mold.

        There’s no obvious reason why one couldn’t do a DIY version of it. The microfluidics coming out of a maker’s garage or basement might have some limitations (e.g. features on the chip might have to be slightly larger), but as long as you’re not expecting to compete with Affymetrix, that shouldn’t be a big problem.

      2. alandove says:

        I just dug up my notes from the Khine interview. She actually already developed a version of the technique that skips the mold process, and uses the Shrinky Dinks directly as the microfluidic. So there’s your solution – it can be done by anyone with a printer and an oven.

  5. Sean Michael Ragan says:

    Just wanted to take a moment to thank all of you for some unusually good comments on this post.

    I was in grad school for organic chemistry when Dr. Khine’s original “shrinky dink” paper was published. I remember showing it around to my lab-mates and peers because I was so excited about it, but almost without exception they just looked at me as though I were crazy, which really confused me at the time. Looking back I have come to believe that most of these folks just didn’t think you could do meaningful science with stuff that didn’t cost a lot of money–the attitude being something like “why waste your time with cheap gimmicky crap?”

    That was well before I started working for MAKE but the blog did hit on her work at the time:

    http://blog.makezine.com/archive/2007/12/labonachip_with_shrinky_d.html

    Although I agree it probably needs to be revisited now.

  6. Dave says:

    So, can an egg-beater-centrifuge be used to enrich Uranium?!?

    Dave