Studying Organic Thermoelectrics Through The CEEM Program

This summer I was given the opportunity to be part of the CEEM summer internship program.  I have zero experience working in a research lab, so going into the program I had no idea what to expect.  So far my experience has been very challenging but even more rewarding.  Even though at first i was very nervous, everyone in the lab has really helped me feel at home and I am looking forward to the coming weeks.

I am working in the Chabinyc lab studying organic thermoelectric materials.  A thermoelectric is a material that can convert thermal energy (heat) into electrical energy or vice versa.  These can be used to capture useless waste heat, such as in factories or even car exhaust, and turn it into useful electricity (via the Seebeck effect).  They can also be used for very precise heating or cooling (via the Peltier effect).  These thermoelectric effects are consequences of the semiconducting nature of thermoelectric materials.  Typically semiconductor devices are made from inorganic crystals with a rigid structure, so these are what make up the majority of current thermoelectrics.  More recently however, people have begun looking into organic polymer (fancy word for plastic) semiconductors, which is what our lab is interested in.  So far these are not nearly as efficient as existing thermoelectrics, but they have the added bonuses of being flexibe, easy to process, and stable at room temperature.

Anne Glaudell, my graduate student mentor, is laying down the groundwork for this research by characterizing the thermoelectric properties of different organic semiconductors.  Unlike inorganic thermoelectrics, not much is known about how organic polymer thermoelectrics actually work.  Before theory can be developed much more experimental data is needed, and until then we will have almost no idea which polymers will be the highest performing (there are a lot to choose from).  My job this summer is to look at PEDOT:PSS, an organic conducting ink that is the most promising thermoelectric so far, and compare it with another conducting ink polymer, poly(thiophene-3-[2[(2-methoxyethoxy)ethoxy]-2,5-diyl) (or Plexcore for short).  I will be measuring the conductivity and the Seebeck coeffiecient ( a measure of how well the material converts between electrical and thermal energy) for these polymers.

Like I said before, I had no idea what to expect going into this.  What I’ve learned is that labwork is an exercise in patience and nothing ever works the first time.  After more than 3 weeks of conducting measurements and preparing samples, I still haven’t gotten reliable data for any of my samples.  In the lab anything that can go wrong, will go wrong, and it seems like for every problem you solve three more appear.  I’ve actually spent most of my time troubleshooting with Anne, trying to find a way to take a good Seebeck measurement for my samples.

Ironically, I can honestly say this has been one of my favorite parts of the experience.  All the little mishaps along the way have given me a chance to try and really understand how everything in the lab works.  From the measurement equipment, to the processing, to the software.  There are problems everywhere you look in lab, and I love problem solving.  The real work in lab is  finding clever solutions to problems when there are no textbook answers.  This whole experience has given me a chance to see first hand how science actually happens and I have a new found appreciation for all the work that goes into it.  In just a few short weeks I’ve met so many great minds and teachers that have really helped me develop and prepare myself for the future.  I’m excited to see how things go the rest of the summer.