Research


 

I conduct biomedical engineering research, in the general fields of tissue engineering/biomaterials, and educational research on teaching and learning. 


Biomedical Research

In general, my research focuses on elucidating and controlling events at the interfaces between cells and their surrounding environment.  I like to get students involved in collaborative projects; usually these projects study cellular responses to mechanical and chemical stimuli, control cell-biomaterial interactions, or mechanically or biologically characterize tissue-engineered constructs.  I'm particularly interested in investigating fundamental issues and questions that are common to multiple cell/tissue types and central to many aspects of tissue engineering. We are always interested in learning something new.

 

Most of our recent research relates to replacing soft tissue lost to burns, trauma, cancer surgery, etc.  The abundance and structural importance of collagen in the human body make this protein a logical choice for the development of biomaterials for a broad spectrum of tissue engineering applications.  The relative biocompatibility of collagen has motivated many researchers to culture cells within collagen gels to create soft tissue equivalents in vitro.  However, many of these efforts have met with limited success because the cells dramatically contract the gels over time - resulting in a construct which is only a fraction of the original size, and compacted enough to reduce the viability of the constituent cells.  To address these problems, we create composite biomaterials, made of collagen fibers embedded in collagen gels.  Long continuous fibers placed within the composites (when desired) alter the tensile tangent modulus of the constructs; the gel phase of the composites is hospitable to cell culture.  Gels containing short noncontinuous fibers are 100 to 1000 times more permeable than gels without fibers, encouraging nutrient transport and the long-term viability of large populations of cells.  Gels containing short fibers maintain their shape, dimensions, and mechanical properties to a large degree throughout weeks of cell culture, while gels without short fibers contract substantially and gels without cells weaken and degrade.  Recently, Rose-Hulman students have developed new techniques to produce collagen fibers with specified cross-sectional areas and shapes, and explored gel-fiber mechanical interactions.  With Rose-Hulman undergraduate and M.S. students, we continue to work on characterizing and controlling mechanical properties of collagen fibers, gels, and fiber/gel composites, and on demonstrating and characterizing the biological multipotentiality of collagen composite biomaterials in various tissue culture applications, with the end goal of creating large, mechanically-sound, and biologically-viable cell/composite constructs.

 

Educational Research

I'm interested in finding, evaluating, and using teaching methods that help students learn - please see my "Publications" webpage for papers. In summary, some of my work has provided evidence that:

- Different people may have different preferred ways of learning; teachers can engage multiple learning styles, inclusively letting students work in their preferred styles some of the time while giving students practice working in other styles the rest of the time.

- Professors who teach courses with high perceived workloads are not automatically given poor teaching evaluations by students.

- Student evaluations of teaching are correlated with aspects of organization, relevance to educational goals, and instructors interacting respectfully and helpfully with students.

- Active learning exercises help students learn - not just because the students 'wake up' and refocus their attention, but because of the pedagogical value of the active learning exercise.

 

Student evaluations of teaching are the most common method of obtaining feedback on perceived course quality and instructor performance.  Traditional evaluation forms, however, tend to be instructor-centered, and to provide little information about students' contributions to their learning.  Capstone engineering design courses are, in many respects, different from other courses in that student contributions to and responsibility for learning experiences are critical pedagogical goals: design problems are usually open-ended and design projects are often student-driven.  We are currently testing and improving a supplemental design course evaluation that assesses the prevalence of selected student practices in design, perceptions of student responsibilities and professional development, and perceptions of instructor roles.  These types of information are not provided by traditional student evaluations of teaching, but are important to design instructors as they work to continually improve design courses.  We are also currently undertaking a large educational research project examining whether specific types of learning experiences, improve student performance in a multidisciplinary, high-workload, rigorous engineering problem-solving course. 

 

 

Last updated 04/13.