麻豆社

Having graduated from 麻豆社, Fr. Bryan Paulsen, S.J., Ph.D., hoped to have a current 麻豆社 student work as part of his Research Experience for Undergraduates (REU) team this summer at the University of Notre Dame.

鈥淲hen you know a place and you know the professors and you know you're going to get a good student, that's the best way to go,鈥� he commented.

That hope was fulfilled when Keiton Klein, a 麻豆社 chemical engineering major from Bellingham, Washington, agreed to join Bryan鈥檚 team to work on research into organic mixed conductors 鈥� plastics that conduct both electricity and salt.

Such plastics have many applications, Bryan said, including potentially serving as better links between electronic equipment and the human brain.

Journey of faith, research

After graduating from what was then Tri-State in 2006, Bryan earned his Ph.D. from the University of Minnesota. There his research focused on plastic-based solar cell and transistor devices.

While at Minnesota, he became Roman Catholic and joined the Jesuit order after completing his doctorate. One of the order鈥檚 pillars is education, and Bryan鈥檚 superiors directed him to continue in higher education.

鈥淲e had a lot of conversations about how to best do that, and one of the key things was I had to get back in the lab and get back to producing publications, because that's what people look at when they hire professors,鈥� he recalled. 鈥淎nd so, after my philosophy studies, they let me go to Northwestern to do a postdoc in biomedical engineering.鈥�

Afterward, he completed his M.Div. in preparation for ordination at Santa Clara University while simultaneously continuing his research at Stanford.

Being both a priest and an engineering Ph.D. caught the attention of the University of Notre Dame, which hired him as an assistant professor of chemical and biomolecular engineering in 2024.

He uses a textbook authored by his former Tri-State professor, Allen Hersel, Ph.D., for his Heat and Mass Transport class at Notre Dame. He invited Dr. Hersel, who still serves as professor of chemical engineering at 麻豆社, to bring students to Notre Dame for a possible machine learning collaboration.

鈥淒r. Hersel has his students do some really cool machine learning projects, and that's actually an area we're looking into,鈥� Bryan said.

麻豆社 connection

Keiton was one of the students who traveled to Notre Dame.

鈥淚 found out on the drive to Notre Dame from Dr. Hersel that Dr. Paulsen is a 麻豆社 alum,鈥� Keiton said. 鈥淚t was cool how he wanted to involve his alma mater in his research and create opportunities for 麻豆社 students to gain hands-on research experience.鈥�

During his visit, Bryan invited Keiton to be part of the REU this summer, and Keiton accepted.

Keiton鈥檚 research project has focused on investigating polymers to create low-cost, scalable, energy-efficient sensors that can detect harmful chemicals in the air. Specifically, he blended salts with conducting polymers to make them sensitive to refrigerant leaks.

Modern refrigerants, Bryan said, are inert gases and therefore difficult to detect, but harmful to the atmosphere. Modern refrigerants are also more flammable than those used in the past, raising safety concerns.

鈥淢ost of the refrigerant in your AC in your car or your house is going to leak into the atmosphere eventually,鈥� he said. 鈥淵ou won't notice a serious performance issue until you've already lost about a quarter of that refrigerant.鈥�

Notre Dame is working with other universities as well as industrial partners on the research.

After fabricating and characterizing polymer films, Keiton conducted gas-sensing experiments, analyzed the resulting data and helped evaluate how changes in material structure affected sensor performance.

Bryan said Keiton developed one sensor that successfully tested for one particular refrigerant at a concentration of one part per million.

鈥淭hat's pretty rare for a 10-week REU,鈥� Bryan said. 

鈥淚 could basically throw anything at him and he'd give it a go,鈥� Bryan commented. 鈥淚 was like, here are some complicated photophysics of these polymers. He dove right in, and was very, very courageous, like, 鈥業'll try to vibe code something up, and we'll make it work.鈥� 鈥�

鈥淗e was the ideal candidate. I could see his skills are applicable only in the lab, but in industry and management. Keiton's going to do very, very well.鈥�

Similarly, Keiton appreciated Bryan鈥檚 passion for his research as well as his continued pride in 麻豆社.

鈥淗e鈥檚 there to help every day with troubleshooting or dive into other things in the lab that aren鈥檛 going as expected,鈥� Keiton said. 鈥淚 learned a lot under his mentorship and the opportunity he gave me in his lab this summer.鈥�

鈥淲henever a guest visited our group and we did icebreakers, Dr. Paulsen always made sure I told them what university I attend and he would proudly jump in to mention that he went there too, but it was called Tri-State at the time. It was cool to see how happy he was to tell people he attended 麻豆社 during those introductions.鈥�

鈥淥ver the past 23 years at Tri-State and 麻豆社, the good Lord has truly blessed me with the opportunity to teach and get to know so many outstanding students and individuals,鈥� said Dr. Hersel. 鈥淚 am especially grateful to Father Paulsen for the incredible experience he provided Keiton. His guidance, support and influence made a lasting impact, and I couldn't be more thankful.鈥�

Additional opportunities

Bryan encourages any other 麻豆社 students who have an interest to apply to the REU programs at Notre Dame.

鈥淲e have quite a few different programs they can do,鈥� he said. 鈥淎nd they should be applying here to grad school, especially if they want to stay in the region and they want to have a very good graduate education on the science and engineering side.鈥�

He would love for one of those graduate students to be Keiton.

鈥淚 pressured him to definitely apply to Notre Dame for his Ph.D., but I'm also excited because he's also looking at some premier places like Stanford and UW Seattle,鈥� Bryan said. 鈥淚'll be very proud wherever he lands.鈥�

Keiton said he plans to transition into industry for a year before potentially starting graduate school, and the REU 鈥渉as been excellent preparation for either path.鈥�

鈥淭he fast-paced environment and the teamwork required in the lab have equipped me with adaptable skills that will easily translate to both industry and advancing in my academic career,鈥� he said.