Conformational switch

Temperature-induced conformational switch of PNIPAM

PNIPAM is a thermosensitive polymer that undergoes a reversible coil-to-globule conformational transition around its lower critical solution temperature (LCST), around 32°C. It switches from a hydrophilic, swollen state to a hydrophobic, collapsed state.

• Download the resizable, editable SVG source file (SVG, 65 KB)

PNIPAM-based immunoassay

Immunoassay based on the thermal precipitation of PNIPAM

The peculiar properties of PNIPAM make it possible to use this polymer as a support for immunoassays based on thermal precipitation.

• Download the resizable, editable SVG source file (SVG, 151 KB)

Cell culture

Cell culture on PNIPAM-grafted surfaces

PNIPAM-grafted surfaces can be used as a soft support for cell cultures. Cells grow on hydrophobic PNIPAM and are softly released by lowering the temperature and making the PNIPAM hydrophilic.

• Download the resizable, editable SVG source file (SVG, 249 KB)

Adsorption and release of proteins

Controlled adsorption and release of proteins on hydrophobic PNIPAM-grafted surfaces

The same way cells adsorb on hydrophobic PNIPAM surfaces, proteins may be reversibly trapped on PNIPAM surfaces, then released upon command. This is actually one of the things I did during my thesis.

• Download the resizable, editable SVG source file (SVG, 63 KB)

Licensing and reuse

All the source files are vector graphics, i.e. they can be resized at will without loss of quality or pixelation. They are released under a Creative Commons Attribution ShareAlike license, which means you are free to use them, modify them, redistribute them for any purpose as long as you appropriately attribute them, and that you distribute any derivative works only under the same license.

Preview of the new resume

I am always looking for new exciting job opportunities. My former resume was a clean scientific resume in its form and layout. I had made it using LaTeX and it helped me find my two latest positions as a researcher. However, as a classic resume, it was as boring as the documents I usually disparage, so I decided to listen to my own advice: make the look support the content.

Its content was pretty stable and up-to-date, so I knew I wouldn’t have to change that much. I decided to focus on its appearance, hence why I chose to make the new resume with Scribus, my favourite desktop publishing software.

A dual-skill profile

I have a peculiar profile. On the one hand, I have had a high-level scientific training in engineering, physics & micro-electronics. I graduated from a top French Grande école and I got a master’s degree in nanotechnologies and nanosciences. I completed my Ph.D in the field of microsystems for life sciences and lab-on-chips. All my positions have been at the crossroads of technology, biology and chemistry (see my article about interdisciplinarity).

On the other hand, I have been working as a communications & marketing volunteer for the Wikimedia Foundation for about two years and a half now. I have answered the press, supported the Foundation’s Head of communications and created institutional documents. I have also co-managed the customer service of the Foundation, recruited new volunteers and recently started a PR material cleanup as the first step before a complete revamp of our PR / marketing material.

A consistent layout and look

I wanted my resume to really show these two sides of my profile. After much thought and many attempts, I came up with a nice two-column design that uses my favourite color scheme (the same as for the new logo of unfoldscience). Each column is dedicated to one side of my experiences and training and leads naturally to the job opportunities I am looking for now.

Interested?

Are you interested in my profile? Contact me to discuss your projects!

Links

• Download the high-quality PDF resume (PDF, 670 KB)

Opening out

In January 2008, I attended the Biodevices conference in Madeira (see my article about Biodevices). I also took a few days of vacation to visit the island after the conference. It was not yet the season for flowers, but it was really beautiful and flowers were growing all over the island; among them were strelitzias, also called birds of paradise. When I saw them, it hit me: they were a perfect symbol of unfolding. Besides, they were orange and blue, my two favourite complementary colors. They were just perfect. I took a lot of pictures of strelitzias and I used them to design a draft logo that represented a bird of paradise unfolding.

A bird of paradise in Madeira

Design principle: user testing is mandatory

First draft logo

Every designer will tell you that no matter how hard you work on a product, you have to seek feedback from users and people who have not been involved in the process. I would even say that the harder and the longer you work on it, the more you have to seek external feedback. In the case of my draft logo, I had worked on it so long that it was obvious for me it represented an opening strelitzia.

However, the first two people I asked did not think of a strelitzia; instead they asked me why my logo was some sort of chimera that would be the improbable result of a one-night stand between a slug and a hedgehog. Thanks to their comments, I managed to see through their eyes and I had to admit they were right, so I tweaked the logo a bit.

Final logo

In order to avoid the confusion with a sludgehog, I added a small stem to the flower. Now, if someone does not recognize a strelitzia at first, they will think it represents some sort or bird, which is much better than the previous mythical creature.

Final logo

Unlike most of the website, this logo is not released under a free license for an obvious reason: a logo is meant to identify a unique entity, and this entity is unfoldscience.

Links

• Download the vector graphics logo (SVG, 23.5 KB)

Preview of the thesis

I am glad to announce that my Ph.D thesis is now available for download. The document, called Technologies PNIPAM pour les laboratoires sur puce (“PNIPAM technologies for lab-on-chips”) is only available in French (University policy), but there are some pretty pictures and infographics in there too for people who don’t speak French; one of them is the “Interdisciplinarity, biology and micro-nanotechnologies” information graphics I published earlier.

Summary

Labs on chips are miniaturized devices integrating one or several laboratory functions, usually dedicated to the handling of chemical and biological samples. Our work aimed at integrating a smart polymer called poly(N-isopropylacrylamide) (PNIPAM) in microsystems, in order to develop a new technological process for labs on chips.

PNIPAM is a thermosensitive polymer that undergoes a reversible state transition; it switches from a hydrophilic, swollen state below its temperature of transition (LCST ~ 32°C), to a hydrophobic, collapsed state above it. The technology we developed is based on heating elements and a surface functionalization process to graft the PNIPAM layer.

Our results show that the electro-osmotic flow can be modulated by thermally controlling the PNIPAM, thus paving the way to electrokinetic mixers. This thermal control also enables the adsorption (and partial desorption) of proteins on fonctionalized beads, the main application being sample preparation.

Keywords: Lab on a chip, NIPAM, microfluidics, thermosensitive polymer.

Tools

I mainly used LaTeX to create this document. All vector infographics were made using Inkscape.

Although the PDF file can be searched as plain text, I have also started to convert the document to wikitext in order to make the whole content available on Wikisource. However, this process takes time and I have other priorities at the moment, so any help is welcome.

Licensing & reuse

I released the whole document under a GNU free documentation license, which means you are free to use it, modify it, redistribute it for any purpose as long as you appropriately attribute it, and that you distribute any derivative works only under the same license. You also have to provide a copy of the license.

Link

• Download the high-quality PDF thesis (PDF, 130 p., 6.45 MB)

Because technology provides the tools and biology the problems, the two should enjoy a happy marriage.

Although this statement is awfully simplistic, biology and technology do enjoy a happy marriage, and I was thrilled to experience it during the last three years. My Ph.D work has been very interdisciplinary and I wanted to dedicate a special section of my thesis to how cool, yet difficult, it is to work at the crossroads of biology, chemistry, physics & technology. Because an image is worth a thousand words, I assembled a nice comparison of various reference biological objects and technological devices at the micro- and nanoscale. Most of the images I used were available on Wikimedia Commons and I made the others.

Biological and technological scales compared

The source file is vector graphics, i.e. it can be resized at will without loss of quality or pixelation. It is released under a Creative Commons Attribution ShareAlike license, which means you are free to use it, modify it, redistribute it for any purpose as long as you appropriately attribute it, and that you distribute any derivative works only under the same license.

Links

• Download the vector graphics source file (SVG, 1.46 MB)
• See the author & licensing information page on Wikimedia Commons, including links to all the images used in this one

Notes

Preview of the poster

In January I attended the Biodevices conference in Funchal, Madeira. Biodevices is short for International conference on biomedical electronics and devices. I presented a poster there entitled Thermoresponsive polymer-based microdevice for nano-liquid chromatography. We could easily have submitted a talk, but my advisors thought otherwise.

Anyway, I reused the design I made with Scribus for MicroTAS 2007 and I came up with a nice poster that I am now sharing with you. Some PDF viewers may have some trouble displaying this file, because it uses transparency and layers. I recommend to use the latest version of Adobe Reader.

As usual, the whole poster (except the top logos & header) is released under a Creative Commons Attribution ShareAlike license, which means you are free to use it, modify it, redistribute it for any purpose as long as you appropriately attribute it to me, and that you distribute any derivative works under the same license.

Links

• Download the high-resolution PDF file (PDF, 4.7 MB)
• Heavy source files available on simple request.

Inauguration

This new cleanroom was recently inaugurated by political representatives. As the official photographer for this event, I also had the opportunity to take a few pictures of the facility itself and its equipment. I released them under a free license and uploaded them to Wikimedia Commons, the free media repository.

Opening ceremony

Sample gallery

All these pictures can especially be used to illustrate the relevant articles in Wikipedia, such as Thermal oxidation or Plasma-enhanced chemical vapor deposition. And once a media file is on Wikimedia Commons, it can be used across all Wikimedia projects, such as Wikipedia in Russian or in Japanese.

Etching tanks

Steppers under inactinic light

Molecular beam epitaxy device

Links

• See the whole category “LAAS technological facility” on Wikimedia Commons

Tools

Most (if not all) of my colleagues use PowerPoint to make their posters. Besides the fact that it is a proprietary and expensive software, it also remains a presentation program suited for, well, presentations. A poster is not a presentation, and there are more suited tools than presentation programs, such as desktop publishing programs.

I have been using an open source desktop publishing software called Scribus, for some time now and I just love it. Scribus supports layered elements, has an awesome color management system and offers a PDF export feature of outstanding quality; it even supported PDF/X-3 export before any other (proprietary) software.

The Great Wave

Posters sessions are usually boring as hell. The presenters often forget that researchers who attend a conference have very little time to devote to the posters. I decided to find an original design to attract visitors who would then learn about my research & results. My poster was about a new way to generate waves in microchannels using polymer-based mixers. I looked up in the “Waves” category of Wikimedia Commons, the free media repository, and I stumbled upon this old Japanese painting called The Great Wave off Kanagawa. I found a high-resolution, high-quality copy that I used as background image for my A0 poster.

Copy of The Great Wave off Kanagawa

Preview of the poster

Outcome: Look matters

Needless to say, my poster got much more attention than its neighbours. Asian people were particularly excited about it, and they represented a large part of the audience. You can catch more flies with honey than with vinegar, says the English idiom. It is also true for scientific communication: you can catch more attention from researchers with original, attractive documents than with boring, poorly-designed ones.

And now it is yours

The high-resolution PDF version of the poster is available for download below. Some PDF viewers may have some trouble displaying this file, because it uses transparency and layers. I recommend to use the latest version of Adobe Reader.

As usual, the whole poster (except the top logos & header) is released under a Creative Commons Attribution ShareAlike license, which means you are free to use it, modify it, redistribute it for any purpose as long as you appropriately attribute it to me, and that you distribute any derivative works under the same license.

Links

• Download the high-resolution PDF file (PDF, 4.4 MB)
• Heavy source files available on simple request.