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LERCIP Participant Diana Santiago
08.17.10
 
Diana Santiago in a laboratory

During her LERCIP internship, Diana Santiago conducted research about solid oxide fuel cells for flight applications. The cells are being designed at NASA's Glenn Research Center. Image Credit: Diana Santiago

In which NASA student opportunity project did you participate, and how did you get involved in it?

I had the opportunity to participate in a summer internship with Lewis' Educational and Research Collaborative Internship Program, or LERCIP. My thesis advisor told me about this opportunity and encouraged me to apply. He is the director of a NASA University Research Center, and he is always spreading the word about the current and upcoming academic opportunities for the graduate and undergraduate students.


Explain the research you conducted through your NASA involvement, and why this topic is important.

Last year I worked with a uniquely low volume, high power density solid oxide fuel cell, or SOFC, that was designed at NASA's GRC (Glenn Research Center) for flight applications. This is one of the fuel cell systems that, with the use of high temperature, convert chemical energy directly to electrical energy. This fuel cell is composed of three main parts: the cathode, electrolyte and anode. But to achieve the desired power density, it is necessary to create stacks, adding another component to the fuel cell: interconnects. These interconnects must have good chemical stability in both oxidizing and reducing atmospheres because it will be separating the anode and the cathode. It also must be compatible with the other components of the fuel cell.

Glenn Research Center has been working to prototype a new SOFC design with innovative processing methods to achieve a high power density (>1.0 kW/kg) for use in aircraft and unmanned aerial vehicles. Current state-of-the-art fuel cells have a power density of 0.2 to 0.4 kW/kg. To achieve higher power densities, the NASA SOFC team created a bi-supported cell design that allows the gas flow through the electrodes and not the interconnectors. The interconnect metal plates are replaced with a thin ceramic layer eliminating approximately 70 percent of weight from the cell. The new design necessitates development of interconnect that can be brought to full density as part of a co-sintered block with the zirconia electrolyte, which requires balancing densification behaviors with the other components of the fuel cell. The SOFC team has been working with lanthanum chromite doped with calcium and cobalt. My summer research project was to determine the composition of lanthanum chromites doped with calcium and cobalt that sinters to full density, maintains cell flatness, and exhibits best phase stability and conductivity at fuel cell operating conditions. I learned the ceramic processing procedures needed to produce these materials and age these materials. I was then responsible for analyzing the microstructural and microchemical characteristics of six different interconnect compositions using scanning electron microscopy, energy dispersive spectroscopy and X-ray diffraction. Finally, I identified the lanthanum chromites doped with calcium and cobalt with the best characteristics. The NASA SOFC research team is currently using this composition in new SOFC stacks.


What has been the most exciting part of your research?

One of the most exciting parts of my research was the opportunity that my LERCIP mentor gave me preparing and assembling a single cell of solid oxide fuel cell. I created my own cells that were tested and showed good results. It is not the same to hear or read about fuel cells than to create a real fuel cell and see the results. That was a nice complement of my summer research.


What is your educational background, and what are your future educational plans?

I have a degree in chemistry, and currently I am a graduate student of the department of chemistry of the University of Puerto Rico at Rio Piedras. I am the first person in my family studying in a graduate school. Currently, I am working in a Ph.D. research project with Dr. Carlos R. Cabrera at the electrochemistry and interfaces laboratory. My research is to develop a new electrochemical technique for a bulk preparation of nanocatalysts for fuel cell applications. This new technique, named rotating disk-slurry electrode, or RoDSE, is the first technique for bulk preparation of nanocatalysts using electrochemical methods. This technique permits the formation of metal particles with particle sizes between less than 1 nanometer to 10 nanometers. The main goal of my research is to electrochemically create quantities of nanocatalysts with the best characteristics for use in the anode of a proton exchange membrane fuel cell or direct methanol fuel cell. I expect to finish my doctoral studies before the end of 2010.


What inspired you to choose the education/career field you did?

I have loved mathematics since I was a child. Always I wanted to go to the next task without waiting (until) my classmates finished the one that I had already finished. I finished, by myself, all the exercises of the math book of the third grade in the first semester. Subsequently, some of my classmates did the same, and when we grew up, we were in special groups taking advanced mathematics courses. This was like play, and at this time I knew that I had to study something related with mathematics. Already in the university, I enjoyed the chemistry classes, first because they use a lot of math and later because in all the chemistry laboratories I saw its application in every day life. Finishing my undergraduate studies, I had the opportunity to work in research and this changed everything. I worked modifying a gold surface with benzenethiol using the self-assembly monolayer method and using electrochemical techniques for its characterization. My advisor encouraged me to follow graduate studies in chemistry and here I am developing an electrochemical technique to create nanoparticles on a large scale.


What do you think will be the most important things you'll take away from your involvement with NASA?

My involvement in NASA changed everything in my life. My thesis topic is related to proton exchange membrane fuel cells using hydrogen or methanol as fuel, but in this summer internship I was accepted to work with solid oxide fuel cells. Although all of them are fuel cells, there are significant differences between them. SOFC uses ceramics, and I had never worked before with this class of materials and their processing methods. This gave me the opportunity to prove to myself how quickly I could learn new things, and how I could integrate knowledge to succeed in the great challenge of making a concrete technical contribution in a short period of time. And I think I had great success in this. I had the valuable opportunity of learning many processes and new concepts, thus expanding my knowledge and abilities. After succeeding in this challenge, I feel that I am obtaining the correct tools and self-confidence to overcome any challenge that I will have to face after finishing my graduate studies. Equally important was my personal experience at Glenn Research Center, since it gave me the opportunity to meet very kind people, whom now I consider my friends. Also, being selected to be in a roundtable with the NASA Administrator Charles F. Bolden and other peers was an unimaginable experience!


How do you think your NASA involvement will affect your future?

I think that the opportunity that I had working in NASA will positively affect my future. The privilege of being accepted and working in NASA could help me in my future plans. For me, working in an applied research environment changed the type of research that I was thinking to pursue in my career.


What are your future career plans?

Right now, I am finishing all the requirements of my graduate school to make my dissertation during the next academic year. As a consequence of this great summer that I had, I am strongly interested in working in NASA after finishing the Ph.D. or postdoctoral (studies with) NASA, in a very good university or in a national laboratory. As well as my family, I have high expectations for myself, and I would like to make a significant contribution in my research area.


What advice would you have for other students who are interested in becoming involved with, or working for, NASA?

When my brothers, friends and I were children, we saw the NASA missions and its technology like a dream. We never thought that we could be nearer to NASA beyond one of its visitor centers. Additionally, I did not know before of all the internship and educational programs that NASA has for students from seventh through 12th grade, and undergraduate and graduate students. For this reason, I never applied previously. Right now, I know that NASA has opportunities for everybody (not only in science and engineering) and with a great working environment. I could say to all students that NASA is looking for people with dreams and promise to achieve NASA visions and missions. NASA is not only about becoming an astronaut; it is much more than that. Just apply to one of the educational programs and see what happens. You will never want to leave NASA.


Related Resources:
>  Lewis' Education and Research Collaborative Internship Program
>  NASA's Glenn Research Center
>  NASA Education