Faculty Q&A: Meet Fei Long, assistant professor of mechanical and aerospace engineering at Michigan Tech
Assistant Teaching Professor Fei Long joined the MAE Department in 2013, first as a post-doctoral research associate for one year, and then as an instructor and faculty member. His areas of research expertise include nanomaterials and scanning probe microscopy, sustainable manufacturing, Machine Learning, and waste characterization and recycling.
What drew you to Michigan Tech?
FL: My journey here has been somewhat unique, but I feel fortunate to be at Michigan Tech. After my Ph.D., I worked as an application scientist at Bruker, a scientific instrument company. While I gained valuable experience, the travel-intensive nature of the job led me to seek a return to academia.
It was a bit of serendipity that Professor Reza Shahbazian-Yassar posted a postdoc opening at Michigan Tech in a Bruker user forum. I reached out, we had a great conversation, and I began my postdoc in what is now the Department of Mechanical and Aerospace Engineering (MAE). Following my postdoc, I continued teaching in MAE while growing my research and publications, and in fall 2024, I was thrilled to join the department as a tenure-track assistant professor. Beyond the professional opportunities, both my wife and I appreciate the friendly and supportive people at Michigan Tech, and the peace and natural beauty of Houghton. Coming from a huge city like Shanghai (with its 24.8 million people!), we’ve truly embraced the Yooper lifestyle.
What is your primary area of research, and what led you to it?
My primary area of research focuses on the challenges of plastic recycling, including moving from characterization to sorting and purification, with the goal of producing virgin-quality resins from plastic waste and promoting a circular economy. This focus is driven by the alarming growth of plastic waste alongside plastic production. The Environmental Protection Agency (EPA) shows 76 percent of plastic waste ends up in landfills, 16 percent is combusted, and only nine percent is recycled.
There are several major bottlenecks in effective recycling. First, current optical sensors like near-infrared and traditional cameras, which are commonly used in material recycling facilities, can’t detect black and dark-colored plastics that constitute more than 15 percent of plastic waste. Then the recycled plastics need to go through energy- and water-intensive washing processes to remove impurities and contaminants, which drive up the cost significantly. Moreover, there is no efficient method to remove the colorants from recycled plastics. As a result, most recycled plastics can’t be used in their original applications. Instead, they are used in applications that tolerate more contamination. For example, recycled milk jugs are used to produce detergent bottles, recycled bottles are used to produce sewer pipes, and eventually it all ends up in a landfill.
To address these challenges, we are developing an online characterization system that combines ultra-fast mid-infrared (MIR) spectroscopy with machine learning. The major advantage of MIR is that it’s not color-sensitive and can provide accurate compositional information of polymers, including black plastics. Our system achieves unprecedented measurement speeds, up to 20,000 spectra per second, and preliminary results have shown almost 100 percent classification accuracy for major types of waste plastic on a conveyor belt. We are also collaborating with the University of Wisconsin-Madison to develop a pilot-scale plant using a novel solvent-based recycling technology called Solvent-Targeted Recovery and Precipitation (STRAP). This pilot plant, located at our 7,000 square feet facility within our APS LABS (Advanced Power Systems Research Center), is designed to process 20-50 kg of plastic waste per hour and is a crucial step towards de-risking the STRAP technology for commercialization. This is a huge teamwork of academic and industrial experts and I believe that STRAP could be a game-changer in the plastic recycling industry. I feel fortunate to be part of this team and contribute my expertise.
What do you consider an important long-term goal for your research, teaching or outreach?
My long-term goal is to establish Michigan Tech as a leader in sustainable technologies and advanced manufacturing, with a focus on waste management and recycling. I envision Michigan Tech becoming a central hub for interdisciplinary education, research, and industry collaboration in this critical area. This involves not only advancing the technology but also fostering a holistic approach that integrates engineering with environmental science, business, and social science to address the complex challenges of sustainability.
What do you hope to accomplish as a researcher and educator over the next few years?
As a researcher, my primary goals are to scale up the online plastic waste characterization system for industrial applications.This involves optimizing the machine learning algorithms, expanding the database, and conducting pilot tests in industrial settings. We are working with several industrial partners to move it closer to commercialization.
For STRAP technology, securing Phase II funding is crucial to further de-risk the technology, both scientifically and financially, and pave the way for commercialization. This will involve extensive data collection from the pilot plant, stakeholder engagement, and targeted grant applications.
In my role as an educator, I am committed to integrating my research into my teaching to give students exposure to cutting-edge developments in sustainable technologies and material science and to provide opportunities for both undergraduate and graduate research. I also aim to develop interdisciplinary courses that bridge engineering with other fields like material science and environmental science, focusing on sustainable manufacturing.
Where are you from? What do you like to do in your spare time?
Both my wife and I are originally from China. Before coming to Michigan Tech, we spent over a decade in Shanghai, a city of nearly 25 million people. This contrast helps explain why we love the tranquility and natural beauty of Houghton so much! In my spare time, I’m an avid fisherman. I also enjoy walking our dog on the local trails, and I’ve recently taken up woodworking. My current project is building a stand for my aquarium.
What’s your favorite book, movie or piece of art?
I enjoy Japanese anime, and a recent favorite is “Kimetsu no Yaiba,” or “Demon Slayer.” I also have a soft spot for ’70s and ’80s rock music; my favorite band is Nirvana.
Have you found any favorite spots on campus, in Houghton or in the UP?
It’s hard to pick just one favorite spot because there are so many great places to explore around here. I love fishing in Chassell Bay, walking on the Tech Trails after work, and driving up to Copper Harbor for the stunning forest views.
Do you have any advice for incoming students?
MAE is a highly multidisciplinary field, so choosing MAE means you’re ready for a challenge! My advice would be to:
- Embrace the challenge: Be prepared to work hard and push yourself.
- Be curious and engaged: Ask questions, get involved in research, and explore different areas within MAE.
- Utilize resources: Take advantage of faculty office hours, tutoring services, and other support systems.
- Think critically: Focus on understanding the “why” behind the concepts, not just memorizing formulas.
- Balance your life: Engineering is demanding, so make time for hobbies, exercise, and relaxation.
- Enjoy the UP: Take advantage of the unique natural environment and outdoor opportunities. It’s a special place to live and learn.