I work in the MBE Lab, which is part of the Materials Department and manufactures inorganic semiconductor materials through the process of molecular beam epitaxy. So what is MBE?

It is the method that creates materials of the highest achievable purity in grown films and involves the use of a large machine with ultra high vacuum contained compartments. Elements are heated in separate cells until they begin to sublime, at which point they condense on a wafer and interact with each other to create a thin film. It is called “beam” because ideally the atoms of the elements do not interact until they settle on the wafer. The term “epitaxy” means that the molecules are deposited in a crystalline form in layers over the substrate.

My main research project is concerned with plasmonics, the practice of using nanostructures to manipulate light through a composite material. I work with a material composed of a semiconductor matrix embedded with semimetallic nanoparticles that is grown by MBE. When light waves hit the nanoparticles, the electric field of the wave causes the free electrons of the nanoparticles to move away from the positive nucleus. The restoring force then pulls the electrons back toward the nucleus. This motion continues, and the electrons oscillate back and forth. Surface plasmon resonance occurs when the light frequency matches the oscillation frequency.

I am working to extrapolate the properties of this material using the observed absorption data. We hope to construct a curve based on the surface plasmon resonance theory that fits the experimental data. Through this process, we can discern features of the matrix material such as the dielectric function and the carrier concentration, which need to be considered when the material is used in other applications.

            As an undergraduate researcher you are not expected to know everything about proper lab etiquette. You are simply a student in training, ideally for graduate school. You will be appointed a research mentor, which will be a graduate student, post-doc, or your Primary Investigator (PI). Who ever your mentor is, they have more experience in the lab and therefore it makes sense that they would have more authority in the lab.  When you have a question related to your research project they should be able to answer without hesitation. Well this is almost always true. What happens when you reach aroadblock in your experiment? Who do ask for help? Your research mentor? What if you ask your research mentor for help and you don’t agree with them?

There was a disagreement that I had with my mentor when I was working in the Fygenson lab at UCSB. I was working on an experiment designed to compare two measuring apparatus’ to see which of the two provides the most precise data. My experiment consisted of formulating vesicles with a mass of approximately 100 attograms. The experiment requires two buffers that osmotically match and have a large density mismatch in order to achieve the required mass. The vesicles were to be formulated in a dense buffer, which would induce a mass increase upon the vesicle by filling the hollow interior. The second buffer would act as the dispersant.

Sucrose and glucose were the buffers originally selected, each at a one molar concentration. Complications arose when we were unable to distinguish the difference between the nanoparticles from the sucrose buffer and vesicles themselves on one apparatus. We decided to change the experiment by lowering the concentration to ~50mM and introducing polyethylene glycol 6000 (PEG 6000) in replacement of sucrose. The increase in molecular weight difference between the PEG and glucose made it possible to reduce the concentration of the buffers. Unfortunately, complications also occurred with the new PEG buffer. The osmolarity data of the PEG buffer was inconsistent.

I decided to approach my graduate mentor with the problem. She asked me to repeat the process in front of her so that she could give input on the situation. She concluded that my technique in measuring the osmolarity of the buffers was incorrect, causing me to collect bad data. I was unsure of what the problem was at the time, but I was confident it had nothing to do with my technique. I have experience with the osmometer and am quite familiar with the data collecting technique.

I proceeded to the UCSB library website, searching the Web of Science for an explanation. I was fortunate to find a publication that addressed my problem. Apparently, PEG displays erratic behavior that prevents one from measuring its osmolarity. It has a property that disturbs the interactions between its molecular structure and water. As the concentration of PEG solution increases, the disturbance of interactions between the molecular structure and water also increases.

I went to my graduate mentor with good news; I had found the real problem. There was clearly a power differential between my graduate mentor and I. I decided not to start an argument when faced with this disagreement as she obviously has more lab experience than I. Yet, I still went to her with good news. I determined that the only way to prove I was correct is to find evidence. I believe I handled the situation in a professional manner.

So when in doubt, do your research, find evidence that will back up your argument,  and you will be able to prove your point.

Winter quarter is nearly over and I never thought I would learn all the amazing things I did in lab. But right from the start, I quickly realized that I had holes in my physics education. I realized that most of the physics courses I have taken were not as relevant to my project in Professor Chabinyc’s lab at first. There were also not a lot of similarities between the physics lab courses and this lab. Of course, there is no denying that these physics courses did set a solid foundation for me. But there was so much more to know. In some discussions that I had with my mentor, I was utterly confused because I have never taken an introduction to polymers class or even a chemical engineering class. I felt like I had to catch up real fast.

It was extremely difficult this quarter to balance twenty-two units and work with extra reading on semiconducting polymers and thermal annealing. After reading a considerable amount of papers, I began to make connections to what I was doing in lab to the material presented in the classes I have taken, filling those holes in my education. I never thought that concepts like free energy were related to changing the morphology of polymers through thermal annealing. (I included an image of a thermally annealed sample obtained through AFM for your enjoyment.) I spent most of my weekends in the library, ten hours at a time secluded in a room, connecting these dots and working on homework sets.When I got home from the library, I would eat dinner quickly and continue working. There were some weekends where I slept less than I did during the week.

Image from atomic force microscopy (AFM). Thermally annealed sample.

I know that I totally sounded like a shut-in from the previous paragraph. You just have to make some sacrifices. You just have to go the extra mile when you want to succeed. You have to put in the extra time to achieve what you want. Plus it’s not like I regret anything. It has been very rewarding. I didn’t want to simply go to lab and do what my mentor tells me to do. I want to understand what was going on; I want to have my synapses firing and creating new connections in my brain. I am very fascinated with organic solar cells and I am committed to the research effort. I would say that this has been the most demanding quarter I have ever hard and it was worth losing sleep. Going the extra mile doesn’t stop here for me; I will be doing more research and reading over spring break. And on a side note, I wish you all good luck on finals! Feel free to approach me if you need a pep talk!

Click this link for 50 ways to take a break! Might be helpful for finals!

The past month has been pretty busy in the lab. I have been working on my project for about 15 hours a week, which is hard to balance along with the tons and tons of school work I get. I am a Pharmacology major so I have had to take a pharmacology lab that meets once a week for 8.5 hours, and sometimes it even goes over that time. In addition to being in that lab class for so long, I have to write weekly lab reports that have sometimes been up to 40 pages long! Don’t get me wrong though, I absolutely love that class, it is probably one of the best classes I have taken here at UCSB, but balancing that class, along with my other classes and the research I’ve been doing has been a challenge. It is important to plan your time wisely every week in order to be able to get everything you need to get finished done.

I also have a job on top of school and research. So time management has been a very important skill for me to develop, or else I could not have been able to get through the past two quarters so easily. Sometimes I stay in my lab a little later to work on powerpoint presentations that I have to prepare every week about my results from each week. It really helps to stay and do this in the lab then worry about working on them at home. This is an example of how I plan my time wisely so that I do not have too much to worry about when I get home from school and I can focus on finishing other school work.

So my main message is: know how to manage your time well when you work in a research laboratory and have a heavy course load (and maybe even a job).

On another note, I have really been enjoying working in the lab this past month because my results are starting to look a lot better. In my last post I mentioned how things don’t always go right and it is important to be patient. The patience is finally paying off and I am seeing some promising things and can’t wait to see where I will go from here!

Overcoming the Stereotype

This past summer I undertook an undergraduate research position at the Massachusetts Institute of Technology (MIT). I worked in Dr. Roman Stockers microfluidics group analyzing the physical interactions between Phytoplankton and Marinobacter. I was in awe when I received the phone call from Monica Orta the program director of the Massachusetts Institute of Technology Summer Research Program (MSRP). I had been accepted into one of the most prestigious summer research programs in the country. You can only imagine the intimidation that I felt when I accepted the offer.  I was in disbelief because I had this ideal that people who accepted into prestigious programs as physics majors were students who had 4.0 GPA, 3 excellent letters of recommendation, publications under their belts, and well, white male protégés. It’s a little ridiculous to idealize the type of student in this manner, but that is what I thought about. I am far from this idealization. I am physics major who does not have a perfect 4.0 GPA, I had 2 excellent letters of recommendation, no publications under my belt, and I am a Mexican-American female who had no idea what physics was until my last year in community college.

When I met the stocker lab I was surprised to find that I was one out of the three women who were in the research group and 1 out of 30 who made up the lab group. It was a bit intimidating but I didn’t let that get in my way. The lab was made up of physicists, mechanical engineers, and biologists. I consider my self a physicist, I mean after all I am getting a degree in physics. Right?! Well, some of the physicists who are part of the research group didn’t think so.  There was a certain occurrence where one physicist pulled the stereotype card on me. The Stocker lab was in the process of conducting interviews for a new lab manager. One of the interviewees had just come out of the group interview with the Post-Doc physicists, who by the way were all men. She came up to me to introduce herself and I noticed that the tag was still on her newly purchased cardigan. I told her right away. She was embarrassed and asked one of the physicist why they didn’t tell her anything. The physicist responded, “Well you were just in a room full of physicist, we don’t notice those types of things”. I quickly responded with, “So, am I not considered a physicist?” I was really bothered by the comment this guy had made. The MIT student population lacks diversity.  This is nothing new.

I wanted to bring up this topic because I feel it’s important in science. I can only speak for the physics field, but I am sure there is a lack of diversity in all sciences. I am a 5’10 woman who loves to put make up on, follows fashion, loves rap music, has a social life, and loves physics. My mom has no education whatsoever and works in the fields. My dad didn’t finish grade school and works as a poker dealer at a casino. No one in my family went to college; I am the first.  I am a Mexican-American first generation low-income minority student in the physics field. I don’t let that get in my way. I have been conducting research since 2011, the year I transferred to UCSB. I participated in the National Center for Earth-Surface Dynamics REU at the University of Minnesota, the Mathematics Engineering Science Achievement program at my community college and UCSB, the McNair Scholars Program at UCSB, MSRP at MIT, and the Center for Energy Efficient Materials internship at UCSB.  So, if by any chance you don’t fit the stereotype of your field of study, don’t dwell on it. You have accomplished by far more than the typical (inset major here)ist because you have had to overcome your own obstacles to be where you are at today. So, go ahead and apply for that Undergraduate Research Position you’ve have your eye on and see what happens.