Interview with Dr. Andres Velasco, Dr. Yu Kyoung Ryu and Prof. Javier Martinez—Winners of the Nanomaterials Best Paper Award

We are delighted to invite the winners of the Nanomaterials 2023 Best Paper Award, Dr. Andres Velasco, Dr. Yu Kyoung Ryu and Dr. Javier Martinez, to discuss the article, “Laser-Induced Graphene Microsupercapacitors: Structure, Quality, and Performance”. The paper was published in Nanomaterials (ISSN: 2079-4991)  and has received a significant amount of positive feedback from our readers.

Biography: Dr. Andres Velasco Santiago is a materials engineer (Universidad Politécnica de Madrid, 2017), master’s in nanoscience and nanotechnology (KU Leuven and Chalmers University of Technology, 2019), and PhD in electronic systems engineering (Universidad Politécnica de Madrid, 2024), where he studied graphene materials for renewable energy generation and storage. Currently, he is a postdoctoral researcher at CEA-Liten (Grenoble, France), where he is developing metal-ion capacitors for beyond-lithium technologies.

Biography: Dr. Yu Kyoung Ryu is Assistant Professor at Departamento de Física Aplicada e Ingeniería de Materiales, E.T.S.I. Industriales. She develops her research at Instituto de Sistemas Optoelectrónicos y Microtecnología (Universidad Politécnica de Madrid). Topics of research: graphene and 2D materials in energy applications and thermal scanning probe lithography. Physics degree from Universidad Complutense de Madrid (2009), PhD at Instituto de Ciencia de Materiales de Madrid (ICMM, CSIC, 2015). Postdoctoral stays at IBM Research Zurich (2016-2017, supervisor: Armin Knoll) and ICMM, CSIC (2017-2020, supervisors: Ricardo Garcia, Andres Castellanos-Gomez). Publications: 27 peer-reviewed papers, 3 book chapters, and a scientific book.

Biography: Prof. Javier Martinez Rodrigo is the Director of the Institute of Optolectronic Systems and Microtechnology (ISOM) from Universidad Politécnica de Madrid in Spain.  The ISOM is one node from the Singular Scientific and Technical Infrastructure (ICTS) of the Ministry of Science and Innovation: Micro and Nanofabrication Cleanroom Network (MICRONANOFABS). He has published more than 45 scientific articles in high-impact journals and is the author of 4 patents. He has participated in numerous research projects, both nationally and internationally, with public research institutions and companies. His research falls within the scope of nanofabrication and nanotechnology and is currently focused on the development of nanoelectronic devices made with graphene, 2D materials, and nanowires for energy applications.

The following is a short interview with Dr. Andres Velasco, Dr. Yu Kyoung Ryu and Prof. Javier Martinez:

1. Congratulations on your published paper and the award it has received! Could you briefly introduce the key research focus and main findings of your paper?
A. Velasco: Thank you very much! Our study looked into a very interesting material, as it is laser-induced graphene (LIG), basically the carbonaceous material that is synthesized after a suitable precursor is irradiated with a specific laser. This material has small graphene-like domains, is conductive and highly porous, making it ideal for many applications, such as energy storage, as we explored in the paper. First, we found the optimal laser parameters to produce the LIG with the best properties. Then, we fabricated microsupercapacitors using this optimal LIG as an electrode and studied the correlation between the material properties (microstructure, graphene-like quality, and level of graphitization) and the electrochemical performance of the devices.

2. Could you share a bit about your academic background and what first inspired your interest in this field of research?
A. Velasco: To me, the development of new energy storage solutions that can drive forward the energy transition away from fossil fuels is key. Working towards that motivates me a lot, so developing environmentally friendly, low-cost materials and devices that can help is a plus. On the other hand, I’m a materials engineer with a master’s in nanoscience and nanotechnology, so I’m aware of the interesting relations between processing conditions, material structure, properties, and performance, which is what we looked into in this paper.
Y. K. Ryu: When we read the bibliography about the LIG field, and we believed that it was a material with a lot of potential for energy storage and sensing applications, we decided to open a research line in our group focusing on LIG. We were very excited about it. This happened in the year 2021. We learnt a lot about LIG processing thanks to this first article, and acquired knowledge that has helped us to push our research with this material until today, regarding the doping and the structure engineering of LIG supercapacitors to improve further their performance.
J. Martinez: When you have studied for a PhD degree in physics and a graduate degree in electronic engineering, it is clear that your interest is in new electronic devices.  For these reasons, this article focused on creating a laser-induced graphene supercapacitor, optimizing all its parameters to obtain the best possible performance.

3. During the course of this study, did you encounter any significant challenges? If so, how did you address and overcome them?
A. Velasco: We had experience in graphene, but not in laser-induced graphene. So, I would say that for this study, the most difficult part was starting almost from nothing. Playing around with a low-cost laser engraver, we realized that under some specific conditions, a polymer was being transformed into a conductive material. From there, and with the help of all the co-authors, we selected some specific conditions and performed a more systematic study on their properties and performance.
Y. K. Ryu: I agree with Andres, the main challenge was to narrow down the number of laser parameters to obtain the supercapacitors with the best performance, given our precursor, 60 µm thick Kapton, and the used CO₂ laser, at infrared wavelength. Because the modulation of several laser parameters can produce a large number of LIG materials with different structures, the researchers must select the ones that are suitable for the target application. This challenge, however, gave rise to intense scientific discussions with the co-authors, which I really cherished.
J. Martinez: I totally agree with Andres and Ryu. We tried to get a graphene supercapacitor with the best performance, so that is why we analyze in depth the most critical aspects in the fabrication process.

4. What was your specific role within the research team, and how did collaboration with your colleagues contribute to the paper’s success?
A. Velasco: At the time, I was a PhD student in the graphene&2D group, so I led most of the experiments, from the fabrication of the samples to the measurement and data analysis. Collaboration was key; we measured very interesting Raman spectroscopy maps of the LIG samples thanks to Dr. Alicia de Andres, a researcher from ICMM-CSIC in Madrid, which helped us a lot with the acquisition and analysis of the Raman data.

5. What factors attracted you to submitting your paper to Nanomaterials? How was your submission experience?
Y. K. Ryu: The most important factor that drove us to submit our paper to Nanomaterials was the wide attention that this journal, in particular, and other journals from MDPI in general, give to the laser-induced graphene field. Therefore, we thought that the publication of our work in the journal Nanomaterials would lead to a large visibility and, in this way, the possibility to share our results with many other researchers from the field. The submission experience was very nice in the sense that the editor and reviewers provided us with several suggestions and constructive criticism that helped us to improve our original manuscript, which has resulted in getting this award! Therefore, we are grateful for the feedback from the journal and the reviewers during the submission process.
J. Martinez: The impact factor of the journal Nanomaterials has been growing steadily over the years. This is due to the high quality of the articles published and the large number of citations they receive. For this reason, we have chosen this journal for our publication.

6. In your opinion, which research topics will attract widespread attention in the academic community in the coming years?
A. Velasco: I think every aspect of energy storage technology is going to attract a lot of attention, and of course, economic and time investment. Of course, low-cost materials for large-scale energy storage (grid level, electric vehicles, etc.), but also the intersection between energy storage and microelectronics. There is a lot of work to be done on miniaturized power sources to drive forward the internet of things, always with a focus on sustainability.

7. What advice would you give to young researchers who aspire to produce high-impact research results?
A. Velasco: Doing research in a field that you are passionate about plays a big role. It feels very good to position your work in the big picture and realize that your contribution, as small as it may be, is a step in the right direction. From there, it’s just a matter of being scientifically rigorous, focused, systematic, but also, very important, having a lot of fun!