Preparing students for capstone design through an inquiry-based junior engineering design laboratory course

Introduction: Biomedical engineering (BME) undergraduate curriculum culminates with a capstone design project, required of ABET-accredited or accreditation-seeking programs. However, the progression towards this experience varies among different programs, with design projects and skills introduced employing different formats and pedagogies throughout the curriculum. Oftentimes, sufficient awareness of the design process, testing plans, documentation, dealing with failures, and project management is still lacking as students enter their capstone design course. Here, we attempt to answer the question: How does a junior-level, open-ended engineering experimental design course impact student skill development and preparation for capstone design?

Materials and

Methods: A junior-level engineering design course was developed in Fall 2022 to address this gap in student development and was offered to cohorts of 140 and 156 students in the Spring 2023 and 2024 semesters, respectively. Employing inquiry-based learning pedagogy, the course is structured around two primary multi-week design modules, each offering several project prompts for student teams to pursue. The project prompts provide limited direction for the teams, requiring effective literature analysis and many design decisions. Some project examples include: designing and manufacturing microfluidic chips for separation or mixing of solutions, designing a signal acquisition device to record and analyze action potentials in frog nerves, designing and testing a tissue phantom for ultrasound imaging, designing and building a functional electromyography-controlled prosthetic, designing and completing a multimodal analysis of synthetic tissue, and designing cryopreservation procedures and hydrogels for storage of tissue cells.

Each project incorporates elements of engineering and experimental design, unique prototyping techniques (computer-aided design, circuit design, 3D printing, laser cutting, CNC milling, soldering, PCB design), computational modeling (finite element analysis), programming (microcontroller, signal processing, data analysis), and multiple forms of documentation (design history file, notebook) and design review presentations. Student teams are expected to use available resources, online tutorials, weekly office hours and open-lab times, and the mentorship of the instructional team to independently navigate and develop their design decisions and activities. The schedule of a 6-week project module timeline is provided in Table 1.
Students’ confidence and familiarity with these skills was evaluated through pre and post-course surveys.

Results, Conclusions, and Discussions: In a pre-course survey, students reported that their main expectations coming into the course were to gain more experience in the engineering design process, teamwork, independent open-ended design, experimental design skills, and real-world problem solving. We observed a notable increase in self-reported confidence with these skills in the post-course survey, as seen in Figure 1. We saw a significant increase in self-reported confidence in technical documentation, engineering and experimental design, and computational modeling. Anecdotally, the level of preparation this cohort demonstrated as they entered their capstone design course in Fall 2023 was immediately recognized by tenured instructors of the capstone course as compared to previous years.

The implementation of a junior-level BME design laboratory course has provided a successful bridge between earlier introductory design projects and capstone senior design. Some student perceptions of key takeaways to support this connection include the following comments:

•“This course has definitely improved my documentation skills. I have had to document and write reports for projects in the past, but not to this extent. It allowed me to become very familiar with what is expected in a formal design report.”
•“My biggest takeaway was gaining experience in working on a design project which is very open ended and up to interpretation. Most projects we have done so far have a known outcome and defined steps to get there, but in this class we had to identify our own goal and design our own experiments which was a new experience for me but I believe I am skilled to handle this for the future.”
•“Frankly, this was the first project I've worked on where success is found when every single member is actively contributing to the state of the design. I've learned to be a more effective communicator and taking the lead to ensure things are done timely and to the best quality. Finally, the design process has become a lot more familiar to me after this semester. I am more familiar with the parts of an experiment which are necessary to consider and how to best validate these parts in accordance with one another.”

Acknowledgements (Optional): We would like to acknowledge faculty, staff, and students who supported the development of this course.