Corey Hewitt is a graduate student at Wake Forest University in North Carolina. He discovered his passion for science in high school and is now conducting research in the fields of mechanical engineering and physics. He also invented a thermoelectric material called power felt.
Tell us a bit about your background, where did you grow up, what did you figure you were going to do when you grew up?
I was born in Chester County PA, but lived on Long Island NY until I was eleven; then, my family moved us to Long Island NC (coincidence?) at which point culture shock began for my brothers and me. The reason for the move was a job offer for my dad to work on a NASCAR team. As displaced fans in the north, it seemed like a logical move. I figured that I would follow along in my father’s footsteps and turn wrenches on race cars as well, but after several summer’s worth of racing jobs, I realized it wasn’t quite as glorious as I imagined. With no educational background, I was destined to be a shop rat. What I really wanted to do was design the cars, so my next desire was to be a mechanical engineer. After eventually starting that degree in college, however, I found myself drawn to the underlying science of mechanical engineering: physics. So my career path took one more turn as I continued down the path of a physicist. Now I don’t do anything related to race cars, but it is still a hobby of mine, and I enjoy physics as my career.
What was the first recollection you had of doing a science experiment?
The first pivotal experiment was a catapult design competition we had to do in my high school physics class. The rules were simple: design any type of catapult that could throw a tennis ball the farthest using the potential energy of up to ten rubber bands. I ended up winning the competition, but it was memorable for something much more important. This was the point at which I realized that designing mechanical objects was much more interesting to me than just fixing them. This is what triggered my desire to initially pursue mechanical engineering, and ultimately, physics.
Why did you decide to go to graduate school and get your PhD?
Once you start learning science, you quickly realize that it is going to be a life-long endeavor if you want to try to fully understand a concept or principle. Additionally, when you get down to the minute details of an issue, it becomes clear that there are many things yet to be discovered. Going to graduate school allows you the opportunity to explore and develop new ideas that have a direct impact on the scientific community with the benefit that you have a network of specialized professionals (i.e. professors, fellow students, research staff, etc.) to help guide you during this growing process.
What do you do as a graduate student? Is it fun?
In short, research. Most of my “research” consists of breaking things and failed experiments, but eventually you get everything right, your data follows your predictions, and you are happy to be a scientist. I basically study and test various properties of the materials I am researching, compare the results to my expectations based off of physical theory, and try to think of ways to improve these properties to obtain the desired set of characteristics.
Tell us about this new material, what can we do with it?
The “power felt” is a thermoelectric material. This means that if I apply heat to it, an electrical potential energy will be generated. This energy can then be used to power small scale electronic devices. The novel thing about the power felt is that it uses layered carbon nanotube films as the thermoelectric material instead of bismuth telluride, which is the most common thermoelectric. The downside of nanotubes is that they only generate a very small electrical energy compared to bismuth telluride, but nanotubes are much lighter, cheaper, and flexible. This allows you to use large amounts of them to compensate for the low power, and since they are flexible you can use them in nonconventional applications such as clothing. Your body heat would be enough to warm the power felt and create electrical energy. Currently, the efficiency of the power felt is too low to make an actual thermoelectric jacket, but through improvement of the materials and optimization of the device design, it may one day be possible.
If it’s called ‘Power Felt,’ who came up with that name?
The name “Power Felt” really evolved on its own after many other names used to reference it in the lab. Plus, the more scientific name of multilayered carbon nanotube/polyvinylidene fluoride composite thin films isn’t very marketable.
Do you get to dream up your own stuff or how do you come up with these ideas?
The basic idea of using nanotubes as thermoelectrics has been utilized in our group for about ten years. I, however, have used my interest in design to revive the research in this area by using device design principles to come up with the layered structure of the power felt. My advisor has really given me free reign to explore different types of nanotubes and device structures to optimize the performance of the power felt.
What do you think you might be doing when you finish your PhD?
Well, I hope to eventually be able to become a professor and have the opportunity to start my own research group. It may not be based on thermoelectrics, but I hope the principles I use in my research are the same. It is rewarding working on a project that is multifaceted, including the full range of development of an idea from initial concept, to scientific theory and prediction, to measurement and characterization, to device design and optimization, and finally to practical application.