They are alive. These conductors, they are alive! And they are evolving at a terrific pace.
Well, I may have lied a little bit. What I am getting ready to tell you about isn’t some kind of animal or plant, or even some bug or bacteria. But most of you probably already knew that… The organic conductors in question are simply polymers that conduct electricity, which by itself might be a bit surprising to some. After all, we grow up used to the idea that plastic is a good insulator yet here I am telling you about plastic that acts like a copper wire. In actual fact, we’ve known about conductive polymers for quite some time, it’s just that they weren’t as conductive and as useful until recently.
Now where exactly can you find these organic conductors? They might actually be closer to you than you think. Because organic conductors tend to be transparent, light, durable and flexible, their possible applications range from solar panels to LCD displays. Those e-book readers that have been getting popular lately? Chances are there are at least a few organic conductors in them. That touch screen phone or music player everybody wants to get a hold of? Touch screens can contain these polymers too. You can also use them to protect sensitive devices (i.e. as antistatic agents) or use them to light up the keys of your phone. And the good part is, they work even when bent, wet or worn out. Of course, that would really depend on the material, but you get the idea.
A big inconvenience of using these kinds of materials has been their rather inconsistent properties – conductivity can vary greatly depending on the manufacturing process. It can also be difficult to produce them, since they are not very soluble, not to mention that many polymers can be quite toxic and harmful to humans and the environment. Currently, one of the most commercially available organic conductor is the polymer PEDOT. However, it is rarely used by itself; rather, it is usually combined with other materials to slightly change its properties, for example to make it more soluble. Because of conducting polymers’ promising future and wide range of possible applications, companies and universities all over the world are working towards improving the technology and discovering newer, better materials.
A couple of months ago, there was some breakthrough research involving McGill’s Dr. Dmitrii Perepichka, who worked in collaboration with Dr. Federico Rosei of the Institut national de la recherche scientifique to discover and engineer organic conductors with new properties. What they were able to achieve is a greater control over PEDOT’s structure. Why is that such a big deal? If you’ve ever taken a Biology or a Chemistry class, you are probably aware of how important structure can be. The main reason for the inconsistency in conductive polymer properties is their lack of structure. In this case, by controlling how the PEDOT molecules get ordered during synthesis, not only can conductivity be improved, it is quite possible to create circuits, where certain parts would be conducting and certain parts would not. The difference from regular circuits would be that this here happens at the molecular level!
So, you could potentially make memory and chips that are even smaller than what we are used to. This would be particularly exciting to those who are trying to develop nanomachines or very sensitive sensors.
Going in line with this thought, other McGill researchers , namely Dr. Gonzalo Cosa and Dr. Isabelle Rouiller from the departments of Chemistry and Anatomy and Cell Biology, respectively, recently unveiled their remarkable progress: the ability to study electron transport on the molecular level. This will no doubt help us understand how these materials work and allow great improvements to their design and application. Another great advancement for nanotechnology.
It might still be too early for this new research to bear fruit, but the message is clear: the technology is improving. Companies are recognizing the benefits of organic conductors and some products are already on the market.
I may not be the most talented diviner out there, but I expect these conductors to become increasingly important and present in everyday applications, so keep an eye out.
● Bolduc, Gisèle and William Raillant-Clark. “Organic nanoelectronics a step closer.” McGill. 15 Jun. 2010. <http://www.mcgill.ca/newsroom/news/item/?item_id=163963>.
● Miller, Paul. “LG’s 31-inch OLED prototype to slice through IFA.” Engadget. 30 Aug. 2010. <http://www.engadget.com/2010/08/30/lgs-31-inch-oled-prototype-to-slice-through-ifa/>.
● Nezu, Tadashi. “Conductive Polymers Improve Characteristics; PEDOT Surges Ahead.” Nikkei Electronics Asia. 20 Oct. 2009.<http://techon.nikkeibp.co.jp/article/HONSHI/ 20090929/175766>
● Raillant-Clark, William . “Striding toward a new dawn for electronics.” McGill. 28
Sep. 2010. <http://www.mcgill.ca/newsroom/news/item/?item_id=168188>.
● Rogers, Dan. “PEDOT findings open opportunities for organic nanoelectronic circuits.” Plastic Electronics. 24 Jun. 2010. <http://www.plusplasticelectronics.com/consumer electronics/pedot-findings-open-opportunities-for-organic-nanoelectronic-circuits-14834.aspx>