Implementation of a “Rapid Design Challenge” in a Cross-Disciplinary Senior Capstone Course and Evaluation of Device Performance

The senior capstone experience within the Department of Biological Systems Engineering at the University of Nebraska-Lincoln is a two-semester, two-course sequence intended to give senior students realistic design experience, working with real projects, real clients, faculty consultants, and teammates to produce a deliverable that meets the client’s needs. Students within this course sequence come from two different degree programs (agricultural engineering and biological systems engineering) and within each degree program from a variety of “emphasis areas”, e.g. biomedical engineering, environmental engineering, machine design. While the goal of this course is for students to experience a “real” design project, we felt that we needed to improve this senior design sequence with an exercise that forced all students through a shared and “complete” design process to help address some of the challenges associated with a crossdisciplinary capstone course. Therefore, beginning in 2010, a two-week, rapid design challenge was implemented at the beginning of the senior capstone design experience, based on a similar challenge developed at Bucknell University. This abbreviated design experience challenges the students to rapidly learn and implement the basic steps of design to produce a functional prototype, which is displayed and tested during a design challenge competition. The challenge presented to students is to design and build a device for a third-world clinic to infuse a cholera treatment solution, at a specific flow rate and time for injection, with specific technical constraints. During this two-week challenge, multiple assignments help move the students through each phase of the design process. Teams are given a budget and time to build, test, and iterate their design before the final competition between teams. The team with a device that most closely achieves the dictated criteria wins the competition. To evaluate the performance of each team, a National Instruments (NI) data acquisition system was developed, which combines NI LabVIEW software and two Micro Motion Coriolis flow meters. The system evaluates multiple parameters of the design, and combines the data with faculty judge evaluations to calculate an overall score. Team scores are displayed on a digital scoreboard throughout the competition. The Rapid Design Challenge (RDC) is then used as an example to introduce future topics in the course. Finally, the RDC has been critically evaluated over four semesters of implementation as part of the continuous improvement and assessment process. This exercise has revitalized the course and ensured that all students share a common and successful design experience. Introduction The Importance & Challenge of Capstone Design Courses Senior capstone design is typically the first real-world experience undergraduate engineering students receive within a classroom setting. While many undergraduate programs contain elements of design and small-scale design projects within a four-year curriculum, capstone design is often the only large-scale project with real clients, budgeting, and potential real-world implementation. Working with clients and in teams on problem identification, design development, and solution implementation are the best preparation for a career in any engineering field. With the importance of senior capstone courses so high, the challenges associated with them are equally high, both in number and scope. Challenges frequently associated with senior capstone design courses, as described by others and experienced in our course are as follows: 1. An atypical course format: Typical undergraduate courses follow the classic structure of lectures, homework, labs, and exams. Capstone courses are centered on nontechnical lectures, project benchmarks, student presentations, and design reviews. The nontraditional course format is jarring to many students. 2. Unfulfilling first semester (for two semester capstone sequences): When capstone design is a two-semester long course, there is typically no tangible deliverable upon completion of the first semester. The first semester is focused primarily on research, project management, and brainstorming. As a result, many students report feeling disappointed at the end of the first semester. 3. Project variety and lack of class unity: In most undergraduate courses, even with group projects, all students work on the same project. Teams can work together and discuss problems. However, in senior capstone design, each team works on different projects with different client needs, criteria, and constraints. As a result there is frequently a lack of class unity. 4. The trap of iterative design: While many of our core courses contain design projects, capstone design is a student’s first long-term design project. For most students, capstone design is the first time they spend a considerable amount of time researching, developing multiple designs, testing a design and then reworking it. Consequently, many students stall in one or more phases of the design process and are unable to progress forward. 5. Introduction to the complete design process: While not the case in our program, for many students, senior capstone design is their first introduction to the complete design process. Lack of adequate design experience can be a major obstacle to producing effective final designs, but more importantly a major obstacle in getting the maximum benefit from the course and the learning process that comes with completing a real engineering project. Across the country, these challenges become compounded as enrollment numbers continue to rise in biological engineering departments. According to the 2011 annual ABET review, bioengineering and biomedical engineering programs saw a 98% increase in the number of ABET accredited programs added in the US over the last 6 years, the highest for all engineering disciplines. In fourth for largest increase was environmental engineering at a 20% increase. These disciplines are all represented within the department of Biological Systems Engineering (BSE) at the University of Nebraska-Lincoln (UNL). The Agricultural & Biological Systems Engineering Capstone Course at UNL The BSE department at UNL was one of the first programs of its kind in the country when it was established in UNL. Our program is ABET accredited and has been ranked in the top 10 programs of its kind by US News and World Report. The department houses two engineering degree programs: agricultural engineering and biological systems engineering. Within each of these programs students specialize in one of three emphasis areas. Agricultural Engineering emphasis areas: • Machine Design • Soil & Water Resource Engineering • Test Engineering Biological Systems Engineering emphasis areas: • Biomedical Engineering • Environmental Engineering • Food & Bioproducts Engineering Our senior capstone course sequence, AGEN/BSEN 470/480, is a two-semester long course (4 credit hours total), for seniors only, designed to give students a real-life design experience. The year-long course is comprised of lectures, guest speakers, and exercises designed to enrich and enhance the capstone project, which is presented formally through design reviews, and student presentations. Students work in teams with real clients on real projects. Projects come from clients such as: local industry professionals, design engineers, engineering consultants, surgeons from the University of Nebraska Medical Center, and professors from within UNL. In addition to their client and the course instructors, teams are also assigned a faculty consultant who specializes in the area most similar to their project. Students must draw upon all of their previous knowledge as well as consult with their client, faculty consultant, and other outside sources in order to define their problem, gather information, synthesize usable criteria and constraints to help guide their final design, and finally, they must apply appropriate technical knowledge and practices to develop the best engineering solution to meet their client’s needs. Throughout the two semesters, teams must work through the design process, produce test data, and reiterate the design process to make improvements on their final design. Final designs, or deliverables, can include models, design schematics, prototypes, and in some cases functional products. The course culminates in a written technical report and an oral presentation given to the department, their fellow students, and clients. Some previous capstone projects include: a stream restoration project, development of an integrated energy and production system for a swine finishing operation, design of a 3D imaging system for orthotic production, design of a standing column well for geothermal energy, development of a post-hole digger evaluation device, design of a radiation shield for the hepatic artery, design and development of a quarter-scale tractor, design of an automated weight filling mechanism for a pilot-scale ice cream manufacturer, design and instatilliation of a laboratory-scale water pump facility, and design of a minimally invasive mitral valve surgical heart retractor. The cross-disciplinary nature of the two degrees and six emphasis areas in the BSE department creates additional challenges in the implementation of a capstone design course. Students, while grounded in agricultural or biological systems engineering, have diverse backgrounds and interests in automotive, biomedical, bioprocess, chemical, civil, computer, electrical, environmental, and mechanical engineering. Due to the diversity of student interests, many teams are crossdisciplinary. While challenging, especially to instructors that must manage multi-disciplinary teams and a tremendous variety of projects and clients, cross-disciplinary teams have been shown to be highly advantageous to students, both in courses and in their future careers. Multi-disciplina