Engineering student recognized for research excellence

Greg Brentrup, a graduate student in the department of materials science and engineering, will receive the 2008 Cooper Scholars Award from the Glass & Optical Materials Division (GOMD) of The American Ceramic Society (ACerS).
Named in honor of the late Professor Alfred R. Cooper Jr., member of the faculty at Case Western Reserve University and prominent contributor to the understanding of many glass phenomena and glass problems, the award is given annually to encourage undergraduate students who have demonstrated excellence in research in glass science or technology.


Greg Brentrup


The award, to be presented at the ACerS society meeting in Pittsburgh, Pa., in October, is in recognition of research Brentrup conducted as an undergraduate student through the International Materials Institute (IMI) for New Functionality in Glasses at Lehigh University. The Institute, which is directed by Himanshu Jain, professor of materials science and engineering, was established in 2004 with a five-year, $3.25-million grant from the National Science Foundation (NSF).
Brentrup built his research project around supporting the Lehigh IMI research team’s novel technique for producing a superior bioactive, or biocompatible, form of glass. The scientists want to use this glass to create a “scaffold” that stimulates bone tissue to regrow without causing infection or adverse reactions in the body. This holds great promise as a solution for osteoporosis, dental repairs, and bone defects.
Brentrup joins the team
Brentrup first connected with the Lehigh IMI research team during the summer after his sophomore year, when he completed a 10-week research internship with the Institute through the Research Experiences for Undergraduates (REU) in Glass program. Brentrup worked under Dr. Hassan Moawad, a scientist visiting Lehigh from the University of Alexandria in Egypt, helping him refine the melt-quench technique used by the research team to produce a dually porous glass.
Glass that is porous at both the nanoscale and the macroscale allows the glass to form better bonds with bone, making it ideal for regrowing bone tissue, compared to traditional bone implants.
Brentrup helped Moawad mix and weigh rock chemical materials for the glass-melting process. He also polished the glass and used optical microscopes to study its microstructure.
“I was really lucky to start my research as a sophomore through the REU program,” he said. “My work that summer was my first time working with biomaterials, which is a huge, upcoming field.”
When the research team develops their glass material, they use a chemical leaching treatment to produce the dual porosity. They noticed that stresses from the leaching process caused a lot of cracking in their samples. Brentrup decided to focus on investigating this weakness and continue his research during his junior year.
Brentrup helped the researchers develop a multi-step leaching-annealing process. They stopped the chemical leaching treatment halfway through and then heated the glass material to a specific temperature, called the glass transition temperature.
“Holding the material at that specific temperature relieves some of the leaching stresses that cause cracks in the material,” he said. “We weren’t able to stop all of the cracking, but now the cracks are fewer and smaller.”
Science through a cultural lens
The next step in Brentrup’s research required him to look beyond the polished surface of the glass to investigate how the heat and leaching treatments affect its atomic structure. Brentrup decided to travel for his summer internship in 2007, spending three months at the Instituto Superior Técnico in Lisbon, Portugal. There, he worked with Professor Rui Almeida, a professor in the department of engineering materials. Almeida had been a visiting scientist at the Lehigh IMI and continues to collaborate with Lehigh’s research team.
Brentrup devoted a considerable amount of time at the beginning of his internship to learning new techniques such as Fourier transform infrared (FTIR) and Raman spectroscopy.
“The [Instituto Superior Tecnico] researchers were really supportive in helping me learn how to use the lab equipment, and also helped me adjust to life in Portugal and learn about the culture,” he said. Brentrup thoroughly enjoyed trying new foods and picking up a new language, but was just as excited about being able to devote his entire summer to his research.
“I learned so much over the course of three months,” he said. “I was given a lot of responsibility and I was able to take the research where I wanted to go with it. Research can be a slow process but when you do a research exchange, there is an emphasis on getting results sooner. You have to focus on smaller goals and get those accomplished. It gets the project moving along well.
The results obtained from all of Brentrup’s research areas have been important in furthering the goal of producing a better bioactive glass scaffold. Jain submitted the research team’s work to the International Congress on Glass and included Brentrup’s contributions. Brentrup joined the team on a trip to the event, which took place in Strasbourg, France, in July 2007.
“It’s been a great experience meeting and working with scientists from other countries,” Brentrup said. “It helps further the research collaboration when you work with people from a wide variety of scientific backgrounds and share ideas and resources.”
Life after glass
Brentrup is now a beginning graduate student in materials science at Lehigh, although his role and research focus has shifted. He is currently working on developing functionally graded steel joints for welding dissimilar metals for power plant applications, advised by John DuPont, professor of materials science and engineering and associate director of Lehigh’s Energy Research Center. Brentrup has other duties in addition to attending classes and conducting his research, including being a teaching assistant for the MAT 10 sophomore lab class this semester.
“The responsibility is a lot greater as a graduate student,” he said. “When you are an undergraduate, the research problem is identified for you and you work on it. But as a graduate student, you take on your own project and come up with both the questions and the solutions yourself.”
The one thing that did not change in Brentrup’s shift from undergraduate to graduate work was his learning environment. Leaving Lehigh for a different graduate school was an option, but Brentrup chose to stay.
“When it came down to it, the most important part of my graduate school decision was who I would be working with,” he said. “It’s more about who you work with than what you work on that makes or breaks the experience. After studying at Lehigh for four years, I knew the faculty and that made it an easy choice.”
—Caitlyn Kennedy