Seongsin Margaret Kim
Assistant Professor, Electrical and Computer Engineering
University of Alabama
Tuscaloosa, AL, U.S.
- B.S. Physics, Yonsei University, Korea
- M.S. Physics, Northwestern University, U.S.
- Ph.D. Electrical and Computer Engineering, Northwestern University, U.S.
Kim is currently directing the Bio-Photonics and Advanced Nanosensing Laboratory at the University of Alabama, working on ultrafast lasers, THz photonics, imaging and sensing, THz nanoscopy to answer the question how (nano)photonics and new imaging can improve and save our lives.
Advice to Students:
First of all, you have to develop your own interests and visions. To have and build genuine interests, you also have to know what’s been studied and what the future will be.
Q: When did you first find that your career path focused on nanotechnology?
Kim: When I first discovered self-assembled quantum dots which were grown almost by accident by MOVPE (almost 15 years ago) and I felt something hit me inside when I examined using scanning electron microscopy. MOVPE stands for MetalOrganic Vapor Phase Epitaxy which is similar to the Chemical vapor deposition, but more sophisticated than thermal process. It requires controlling gas phase and laminar flow, which can be done with specially designed reactor. It is well known for growing and (even manufacturing) high quality epitaxial layers (like thin film) until then. I was doing research on highly strained epitaxial layers to make lasers and detectors. I already had a device which performed world record of high power and high reliability lasers and was working on increasing wavelengths which would be suitable to data communication application. To obtain desired wavelengths of lasers, I needed to make highly strained materials but I couldn’t get very good results for a while and struggled to make it better. Then I realized something was not right. What I observed was not just a defect, but it was the self-assembled quantum dots naturally formed because of the strain, and that create small dots (like 10-20nm in diameter). It was nature and so beautiful.
Q: What current nanotechnology applications are you working on?
Kim: I am currently working on hybrid 3D nanostructures for energy harvesting, sensing, and imaging. I have had an increasing interest in science and technology of interface and integration of different types of nanostructure. There are many different types and materials of nanostructures and most of them have been developed and investigated either for specific applications or specific physical properties. I have worked on quantum dots quite a long time, and then I recently have been doing research on Nanowires which demonstrated very interesting properties. It was very natural for me to think how to combine (integrate) quantum dots and nanowires that can leverage different properties in nanostructure. I believe it will have synergetic effects if they can be integrated properly. One example is hybrid quantum dots and nanowire photovoltaics. Photovoltaics (solar cell) is very well known. We have been doing research on new device structure based on such hybrid structure, in which nanowires can be the path to transfer electrons, and quantum dots can be absorption medium of photon. Such a structure is expected to increase of efficiency based on theoretical calculation. Other area is sensing and imaging, where QD can store and attach molecules so that yield higher sensitivities.
Q: What's the most rewarding thing about working with nanotechnology?
Kim: It always brings me down to the earth to question myself. It always has driven me to work better and harder to fully understand the nature. Once I was fascinated by the universe and that directed me to become a physicist first, but the nanoworld is an exact mirror of the universe, where you can find the answers as well. Developing technology to understand both fundamentals and the universe is most rewarding.
Q: Is there an example you can provide that shows how something you’ve worked on has positively impacted the world?
Kim: Since I first made self-assembled quantum dots, I was the one of the pioneers to demonstrate QD-infrared detectors, and QD lasers later. It impacted on a few defense industries and optical communication industries. In general, quantum dots are used in many different applications. Drug industry and bio-medical industry might be the one of the most beneficiary field of QDs. QDs is used for coatings to improve the efficiencies of solar cells and other optical materials.
Q: What do you think is the single greatest impact nanotechnology has had on the world thus far?
Kim: In general, I believe nanotechnology has continuously made an impact on our daily lives. New fabrication and processing technology realized really small devices that helped overcome Moore’s law and ICs continued to improve. However, the most important impact nanotechnology has had might be the capability given to us to change and open our view by discovering the whole new nano-world. As seeing details of biological systems, for example, or sensing in nanoscales, we were able to build new concepts and new applications.
Q: Please give an example of what you envision nanotechnology applications leading to in the future.
Kim: I envision nanotechnology applies everywhere in the future. Fast and small chips will change the computer and information technology (as we have experienced already). Nanosensors can deliver the drugs in your body, may give warning signals for developing diseases (far before it actually happens), virtual networking, imaging that can analyze your feeling, new displays, etc.
Q: Do you find yourself working more in a team situation, or more alone?
Kim: It is hard to tell. I work alone if it is needed, but I also work with team very often since the projects need diverse expertise.
Q: If you work more as a team, what are some of the other areas of expertise of your team members?
Kim: The most successful and interesting collaboration I have had was with one of my colleagues at Stanford School of Medicine, when I was at Stanford as a research associate. It opened me to work with completely different fields and was a most challenging and rewarding experience. In many other projects, I work with materials scientists, physicists, and chemical engineers.
Q: Did your university training help you in your nanotechnology work?
Kim: Not sure, but I am sure University helped in many ways. They provided facilities, some necessary equipment, and most importantly the environments to form communities with a shared interest in Nanotechnology.
Q: Do you have a mentor? Did you in your college years?
Kim: I always have tried to look up and find mentors either inside in my institution or outside of institution. In my college years, it was easier to find mentors and I also liked to be a mentor for my juniors to help them get through tough situations. When I become a professional and now in academia, it has been very difficult to find any in the same institution, and I usually go out to find other seniors and mentors who have been successful in his/her career and in similar research interests. I would like to be good role model for female engineers so I can mentor them to be successful in this research field.
Q: If you had to do it all over again, would you still focus on nanotechnology applications?
Kim: Of course I would. I’ve been working on this field almost 15 years, and I am still most of time (not all the time any more at least) fascinated by all the discoveries and potentials to make our life better and stronger.
Q: If a high school or college student was interested in nanotechnology, what advice would you give them to help prepare take on those roles?
Kim: First of all, you have to develop your own interests and vision. It would not be easy as it sounds, but having the interest and desire to learn is the key factor to make you persistent and move forward -- and maybe someday you will find yourself to be an expert. To have and build genuine interest, you also have to know what’s been studied and what the future will be. I used to read lots of science journals, which are published for those who don’t have any specific background.
I also believe that you have to have your dreams and goals. Dreams -- like how to help others, how to make this world better, and how to make everyone live better -- will make you search and find the solution -- and sometimes the answer is in technology including nanotechnologies.