Lance Yarbrough
Author: Lance Yarbrough | Major: Mechanical Engineering and Physics | Semester: Fall 2023
Blurb:
My name is Lance Yarbrough, and I am in both the Engineering College and Fulbright College of Arts and Sciences. I’m a senior in Physics and Mechanical Engineering, and my mentor is Hugh Churchill from the Physics department along with Dr. Wejinya in the
Engineering department. I am currently in my 4th semester of research with Dr. Churchill, and I am planning to continue research through my last semester through Graduate school at the University of Arkansas.
Research Details:
My research is directly related to the mechanical exfoliation of 2D materials, which are used in quantum computing and q-dots. My specific research, however, is focused on the exfoliation process for graphene, which is used to create thin-layer crystals for production of quantum computing. I am studying the factors that affect the quality of flakes, such as temperature, material properties of tape, and peeling force. I will suggest optimal flake exfoliation processes and apply them to the MonArk Quantum Foundry pipeline in my mentor’s lab.
I found my mentor, Dr. Churchill, through multiple Physics courses I had with him. I took University Physics 2 and Modern Physics with Dr. Churchill and took an interest in his passion for physics and how my learnings in class directly applied to his research. As a double major, I wanted to find a project that fell in between Mechanical Engineering and Physics. The mechanical exfoliation process was a natural fit because dynamics and material science from engineering is studied, but modern physics and experimental processes from physics are also looked at in depth. Later in my college career, I found Dr. Wejinya through his vibrations class, and his natural interest in the research I was conducting. The project then became a joint research project with Dr. Wejinya and Dr. Churchill.
This past semester, I have been preparing to simulate and perform physical exfoliations of graphene flakes. Throughout my research, I have wanted to study what specific variables make the most impact on the quality of flake. This semester, I have specified that I want to look at temperature, force of pull, and number of pulls. In addition, I have decided the temperatures, forces, and number of pulls I want to look at. As time permits, I plan to extend this research to encapsulate speed of pull, different sources of graphene, and other possible influencers to the exfoliation process.
I have worked with Josh Goss to develop an exfoliation platform that would hold tape and perform different test pulls at consistent conditions. Along with this, I learned how to program the exfoliator with G-code, a common coding language in Engineering Industry. In addition to this, with the help of Dr. Wejinya, I have been learning ANSYS to simulate the adhesive and brittle fracture mechanics of the tape pulls. This is a common engineering analysis tool and is often used in simple cases to see if a part will break. By the end of my research, I will become proficient in the tool, and will feel comfortable applying my knowledge of ANSYS to industry work.
By the end of January, I plan to have all my initial physical and simulated test pulls done. I would like to do 5 tests for each metric, expanding as I have time in the following weeks. In addition, I will begin to gather results qualifying what is the best setup for exfoliation. After this main step, I will begin analyzing the data I have taken over the past semester. This research should provide development in the field of automating 2D material exfoliation, and I hope to present my research sometime next semester.
Throughout this past semester, I have been using my funding to buy graphics cards I need for FEA. Due to the Honors College Grant, I have been able to learn ANSYS, an engineering program that is often used in industry. I have been granted an opportunity to directly apply industry knowledge to my research, and I will be more marketable for companies in the future. In addition, I have had funds put towards the exfoliator. This project and learning how to use Gcode has again given me skills that taught me how to formulate projects, develop ideas, and carry them out and apply a tool that works. I have been afforded a hands on opportunity to enrich my skillset, and have applied this opportunity to bring progress to my lab and the field of mechanical exfoliation of 2D materials.