[:en]Natsumi Komatsu
Hometown in Japan: Saitama
Home University in Japan: Keio University
Major & School Year: Applied Physics and Physico-Informatics, B4
Host Advisor: Prof. Junichiro Kono, Dept. of Electrical & Computer Engineering
Host Lab: Kono Lab

Why TOMODACHI STEM @ Rice University?

My last year’s undergraduate exchange program at Rice University was a stepping stone to my passion, to gain English communication skills and strong research background in America. After getting research experience under the supervision of Professor Kono, my passion grew from this achievements and I decided to apply for graduate programs in America. To successfully integrate myself into the American academia, however, I needed more experience conducting research independently like American graduate students, and want to learn to actively participate in discussions. Thus I decided to apply for this perfect opportunity to meet my needs.

After the exchange program at Rice University, I realize the crucial importance of global interaction in research. I wish to use my prior connections and experience at Rice University to help other participants. My wish is so that they have great experiences in research and furthermore expand the benefits of this program, ultimately encouraging more exciting collaboration between Japan and US.

I strongly believe this program will be an indispensable opportunity to get myself prepared for survival in graduate school, leading to the success and the contribution to the world ultimately. Thus, I would like to participate in TOMODACHI STEM @ Rice.

Goals

• Gain experience to conduct research independently
• Learn how to participate in discussions actively
• Use my prior connections and experience at Rice University to help other participants
• Investigate what prevented more than four multi layer structure, and fabricate a terahertz polarizer with better performance

Excerpts from Natsumi’s Weekly Reports

• Week 01: Arrival in the U.S.
• Week 02: First Week at Research Host Lab
• Week 03: Interview With a Female Researcher
• Week 04: Research in the U.S. vs. Research in Japan
• Final Research Poster Presentation
• Week 05: Science & Technology Policy Study Tour
• Final Report

Week 01: Arrival in the U.S.

What surprised me was how much people in the United States were surprised by “ten female STEM students”, because I did not expect them to be surprised by this. This is related to what I talked about during the interview. The difference between “being a female in STEM” in Japan and in US for me is that I feel I am treated as “a woman” in Japan, while I feel I am treated as “a student” in US. I thought that was because of female STEM population; the United States has a larger population of female STEM students. However, by seeing how people react to “ten female STEM students”, it is unlikely that it is the matter of population. Now I assume it is because of culture. I assume people in US think it is rude to point out “female”, like they think it is rude to point out races.

As for seminars, the one about intercultural communication given by Sarah was helpful for me. During my exchange program at Rice, there were times I could not make myself clear enough to others, or I could not understand how others behave. But when I listened to her presentation, it suddenly all made sense. I and others could not understand each other, because the misunderstanding came from the bottom phase of the “cultural iceberg.” I wish I had known this much earlier, and I think this is something everyone in diverse communities should know. Also, what impressed me was how to overcome these cultural differences in the field of research. Understanding is important, but also, as Sarah said, we have the same goal, which made me feel relieved. Most importantly, differences might make things more difficult sometimes, but as long as we have the same goal, I believe it also makes us stronger by having not only one perspective.  This is what I like about working in a diverse environment.

Research Internship Update
As preparation before my arrival in the U.S., my mentor gave me one paper. After reading it, I started looking into the references the paper cited, and other papers from the group where the author is from. I especially recommend to look into papers from the same group, because then you can see the history of that research area within the group.

In general, especially for those who do not have prior research experience, I recommend not to start from reading papers, except for review papers. For beginners, it is difficult to get the idea of what is happening in the field, because one paper is often about the small progress in that field. Instead, I highly recommend to start from looking into websites or textbooks so that one can realize the principles or definitions first. Searching for lecture videos from universities on YouTube is also a good idea. After understanding the basic ideas, now you can start reading papers. It might sound time consuming, but it will give you deeper understandings.

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Week 02: First Week at Research Host Lab

My mentor is a first year Post-Doc in Prof. Kono’s group. He also received his Ph.D. degree from the Kono Lab as well. What I respect about him is his teaching skill and his respect for others. He is a great teacher. He knows many things in detail, but he is good at making them easy enough for beginners to understand. Also, he answers every question very kindly. I used to be afraid of asking “stupid” questions, but because he has never made fun of my questions, now I can ask any question that comes to my mind. He understands that this is part of my learning process, and he always treats me with respect. From his attitude, I learned that “respect” is one of the most important things when I work with others.

Outside of laboratory, the most impressive event for me was to visit Japan Consul General’s house. I was first impressed by the size and the strength of TOMODACHI Initiative network. There were some TOMODACHI alumni, and they were hoping to keep connecting and contributing to TOMODACHI networks, showing how big effect TOMODACHI programs made on them. Also, I got a chance to make a speech about what I have learned from studying abroad and how it changed my life. I was happy that many people came to me to show their symphasy and support. This leads to one important conclusion, and I would like everyone who is reading this to know; if you have a strong will and if you work hard for achieving it, there are many hands to support you.

Research Project Update
There are two projects for my visit: Separation of single wall carbon nanotubes (SWCNTs) based on chiralities and optimization of the filtration condition for dye-inserted SWCNTs.

For the first project, the goal is to get single chirality of (6,5) SWCNTs out of a mixture of chiralities. Aqueous two-phase extraction (ATPE) was used for this purpose[1]. Dextran and polyethylene glycol (PEG) were used to make two phases, and SWCNTs were separated into two phases based on different affinity.

For the second project, the goal is to make aligned film of dye-inserted SWCNTs. It is shown that, by inserting dyes into SWCNT asymmetrically, SWCNT shows a large total dipole moment[2]. If SWCNTs are aligned to each other, this should be enhanced. In order to make SWCNTs alignment, the vacuum filtration system[3] is used. Characterization is done by 660 laser absorption measurement system.

Timeline

• First and second week: SWCNTs chirality separation
• Third week: Optimization of the filtration condition for dye-inserted SWCNTs
• Forth week: Filtration of dye-inserted SWCNTs with applied electric field

References

[1] Fagan, Jeffrey A., et al. “Isolation of Specific Small‐Diameter Single‐Wall Carbon Nanotube Species via Aqueous Two‐Phase Extraction.” Advanced Materials 26.18 (2014): 2800-2804.

[2] Cambré, Sofie, et al. “Asymmetric dyes align inside carbon nanotubes to yield a large nonlinear optical response.” Nature nanotechnology 10.3 (2015): 248-252.

[3] He, Xiaowei, et al. “Wafer-scale monodomain films of spontaneously aligned single-walled carbon nanotubes.” Nature nanotechnology (2016).

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Week 03: Interview With a Female Researcher

My student interview was with Yeobi, who is a Korean sophomore student majoring in statistics. She grew up in Korea until high school and then came to Rice. She wants to go to medical school after getting Bachelor’s degree to get a medical Ph.D.

One important conclusion I obtained from this interview was that we do not recognize ourselves as “female” STEM students at Rice University. Firstly, it is because the number of female STEM students are is not very small. The second reason should be the concept of equality in the U.S. At least, I feel people in the U.S. have a culture of trying to treat people equally, so I do not feel like I am being treated special just because I am a female student in engineering. However, as she mentioned in the interview, the meaning of “being a female STEM” would change when we get older; when we are having children, we might not able to be treated equally anymore. It might be difficult to acquire understandings that our body needs more rest than it used to be. Thus, we both thought “being a female STEM” and also the role of it would change when we grow older.

From this interview, I realized the difference of motivation to study or work abroad. In Korea, when getting a job, there are not many options for STEM students and it is extremely competitive. In terms of the working environment, the status of women is still very low; women have to serve tea for men in the company. When they have a kid, there is not enough child care facilities, so women cannot keep working. On the other hand, in Japan, even though it still has a long way to go, the situation is better. Thus, I had the feeling that Korean students came here because they had to, whereas Japanese students came here because they wanted to. This might explain the reason why many Korean people study abroad while not many Japanese do.

I also asked questions about the educational system in Asian countries. She told me in Korea, everyone studies extremely hard until they get into college and not at all during their undergraduate years. The situation is the same in Japan. She told me “I came here because I actually wanted to study hard and learn many things in college, not just drinking all the time.” I sympathized with her because that was part of my motivation to study abroad too, and I was surprised by how hard U.S. students study. Even though we might not “have to” study abroad, as in Korea, I hope more people do so that they can understand the importance of the intense four-year college study.

Overall, we did not talk much about differences between female and male students, but I obtained a deeper insight of Asian cultures. This is another reason why I want more and more Japanese students to study abroad; you can of course learn about Japan in Japan, but you will never know how global society looks from within Japan.

Research Project Update
This week, I worked on improvement of alignment of dye-inserted carbon nanotubes (CNTs). The vacuum filtration method was used to make CNTs aligned films. No film was obtained with CNT concentration of 2.2 μg/mL at first. Thus, oxygen plasma treatment was introduced to change surface potential. Different treatment time (0 – 40 sec.) with different CNT concentrations (2.2 – 6.6 μg/mL) has been tested, and the best reduced linear dichroism (LDr) of 0.57 was obtained with 10 sec. treatment time and 4.4 μg/mL CNT concentration. This film was characterized by Raman spectroscopy. It was sent to another member (Fumiya) to characterize absorbance near wavelength of 500 nm as well. Next week, I will work on applying electric field during vacuum filtration to see if the alignment can be improved.

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Week 04: Research in the U.S. vs. Research in Japan

In my lab in the U.S., I felt that the graduate students have more freedom to choose what they want to work on than in Japan. But it has to come with background and knowledge. For example, if you want to present a new project to the professor, you cannot just say “I want to try this.” You have to be very precise and you have to know how it works, such as “there was this paper just coming up, this is the theory behind it, and I want to introduce this method to our project because it will have this effect.” At first, this sounded like a lot of work for me. However, it means you can work on whatever you wish to, instead of just working on whatever the senior researcher told you to do. I think this is one of the big differences between research in Japan and research in the U.S., especially in universities, and this is something that makes research in the U.S. more attractive to me.

As for the poster session, one thing I regret is that I was prepared to answer any questions from professionals in my field and non-scientific people, but not from “not professional in physics but still science people”. Although the ultimate application of my project is physics, the method I used was a chemistry related one. Therefore, a few people were interested in how it worked, and asked me about the mechanism, theory or specific questions about the  solution I used. However, because I had been focusing on the physics side of my project, I was not familiar with their questions. To be a good presenter, I realized it is important to know what you are doing from various perspectives, not just from your field. The poster presentation also made me realize what I will miss about Rice: people. During the poster presentation, a lot of people including members of my lab, friends, teachers and their families came… It was an indescribable feeling to know that people here care for me. I realized the research knowledge or experience was not the only thing I earned, but I earned great relationships here at Rice, which made me happier than anything else. I sincerely appreciate every single person I was meet at Rice and their great care.

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Final Research Poster Presentation

Project Title: Aligned Film of Dyes Inside Carbon Nanotubes to Yield a Large Nonlinear Optical Response (PDF)

Host lab: Professor Kono’s lab
Host professor: Professor Junichiro Kono
Mentor: Dr. Weilu Gao

Introduction: When the incident optical field goes in to the dielectric media, because of electromagnetic interaction inside that media, propagation properties such as frequency of this field changes. This is called nonlinear optics (NLO) response. One of the most famous application of NLO is laser; in green laser, 1064 nm light gets converted into 532 nm light by NLO. Usually the inorganic crystals are used for these applications, however alternative of organic molecules has strong and fast NLO response, and it enables cheap and solution processing. However, in two or three-dimensional bulk, these molecules make pair-wise structure, which cancel out the NLO response. In 2015, C. Sofie et al.[1] demonstrated that DANS (organic molecule with dipole moment) inserted carbon nanotube (CNT) shows the huge hyperpolarizability of 9,800×10-30 e.s.u., and if the aligned structure of these CNTs are achieved, it should show higher hyperpolarizability. Thus, my project was to make an alignment film of these CNTs, and improve the alignment.

Approach: We used the vacuum filtration [2], which is the one of the most simplest way to make an aligned film of CNTs. Characterization was done by 660 nm laser absorbance measurement system. To change hydrophilicity of the filter membrane, oxygen plasma treatment was introduced, and several treatment time and several CNT concentration were tested. Finally, we tried to apply electric field to the filter membrane to get better alignment.

Results and discussion: As for oxygen plasma treatment, no film was obtained without treatment because of hidrobydicity, and no alignment was obtained with longer than 40 seconds treatment time. With treatment time of 10s and CNT concentration of 4.4 μg/mL, the reduced linear dichroism (LD^r) of 0.57 was obtained. LD^r indicates the degree of the alignment. As for applying the electric field, every CNT solution passed through the filter membrane in the first try, and we spent almost one week to figure out the reason. It was not because of the dipole moment inside, because all solution went through with or without DANS inside. We believe it is because of Au sputtering, because no film was obtained with Au sputtering but the film was obtained without Au sputtering. Furthermore, when we tried the thinner film thickness (which means shorter Au sputtering time), the filtration speed was very close to the one without Au sputtering.

Future Research: The effect of Au sputtering to the filter membrane should be investigated. Since the filtration speed with thinner film was very close to the one without Au sputtering, applying electric field to the filter membrane with that condition should be tested. Also, the measurement of hyperpolarizebility should be done.

Conclusion: The hydrophilicity of the filter membrane is the important factor to make aligned films. Au sputtering changes the surface condition of the filter membrane.

Acknowledgements: I appreciate Professor Kono for giving me this opportunity and Dr. Gao for his consistent and great support.

References

[1] C. Sofie et al., Nature nanotechnology, 10, 248-252 (2015)

[2] X. He, et al., Nature nanotechnology (2016)

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Week 05: Science & Technology Policy Study Tour

This week, I realized the diversity of career paths again in the United State. Before going to Rice, I thought there was only one way for my future; getting bachelor’s degree, getting master’s degree from the same institution, and getting a job by entering the job market. I thought this was the path everyone in STEM fields took, and this was the path that I should follow. However, this week, I met people working in the government both with and without master/doctoral degree, I met people who went back to school after a few years of working, I met people who got married during school, and I met people who changed their field dramatically after several years of working. Clearly, there was nothing like “the career path I have to follow”, and I realized there were more options than I had thought of. I was happy that my perspective was widened by meeting those people and talking to them.

Also, I was happy that I began not to feel uncomfortable with being visible. When I was in Japan, I tried my best to be invisible because I believed in the saying: “The nail(stake) that sticks up gets hammered down.” For example, when people asked me “any questions?” at the end of their presentations, I never asked any even if I had one. However, soon after arriving the U.S., I realized if I stayed invisible, people would not notice me and I would not get any chance of networking. So, I started to try asking questions. I had difficulties at first because I had to pay careful attention and I had to have a certain amount of knowledge in order to so. But the more I tried, the better I got. And finally, this week, I was happy to find myself comfortable with asking questions in front of others. It was one of the most important changes of my personality through my study abroad experience.

The realization of the diversity in the U.S. and my own improvement made me hope to stay in the U.S. after graduate school. The experiences from this week were very helpful for that, and I appreciate every person I was very lucky to meet this week.

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Final Report

There are important things I learned both in terms of research and for my future career.

As for research, I learned the importance of having solid background knowledge and active discussion with others. There was one time the result of one experiment was totally different from our expectations. We could not guess the reason for that, and there were so many parameters that might have influenced it. I needed to investigate which parameter was the real cause from a lot of factors, and in a productive way because I had limited time. The cause was successfully found, and I guess there were two keys there. First, I kept having discussion with my mentor about the outcome of experiments. Second, those discussions were productive because I had enough background to do so. I was glad that those discussions helped me understand the purpose and mechanism of what I was doing, because I do not like doing what I do not understand. However, without enough background knowledge, sometimes mentors have to tell just what you have to do, and you have to do that without knowing the mechanism. Thus, this experience made me realize the importance of discussions with enough background knowledge.

As for my future career, I learned the importance of networking. Through this program, I had a lot of opportunities to talk to successful people from various fields. One interesting observation was that even though they are from different fields, they had the same answer to one particular question. When I asked them “What led you to the current successful position?”, they always answered “networking.” This surprised me a lot, because this is usually different from Japanese system where all the people right after graduation do job hunting at the same time. One lady from a consulting company even told me there is a survey which revealed that two thirds of people in the U.S. got their jobs from networking. I also found networking was not just for getting jobs. It is helpful to get advice or opinions from others. I found it very meaningful to hear opinions from those who have more experiences in life then you and have different perspectives. I was not good at it yet, but I decided to improve my networking skills.

My advice for future candidates would be to read papers related to your projects as much as possible. You might think your spoken English skill smight be the most critical thing, but getting into this program means your English is good enough. Also, there are many international graduate students in the U.S. so people usually have very good understandings about non perfect English. When it comes to research, whether you understand the project or not matters more. Reading papers related to your projects would help you understand what is happening in the field, what is the issue, what is the mechanism, and make you familiar with scientific words in that field (this will help you communicate well with your mentor!) After getting to Rice, try to ask as many questions as you can! It will show you interest about research. People like students with great interest, so asking questions will help you have a good experience in the U.S. culture.

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