First Year Experience And Beyond: Using The Engineering Design Process To Support Learning And Engineering Skill Development

First-year engineering programs increasingly introduce a focus on the engineering design process, responding in part to accreditation needs and industry advice. Yet too often these introductions to the design process are one or two semesters only, resulting in students not having time to either complete genuine design projects or not absorbing the process sufficiently to be able to apply throughout their academic years. This paper describes a service-learning project that began in a onesemester introductory course, but that continued over three semesters. Students from a variety of majors in the College of Engineering and Applied Sciences (CEAS) at Western Michigan University, enrolled in a first-year Introduction to Engineering class in Fall 2005, worked in teams to design a working prototype of a demonstration kit for a local high school science teacher. The demonstration kit was intended to safely teach x-ray diffraction of a single crystalline solid (by substituting lasers instead of using harmful x-rays) and to allow the high school teacher to demonstrate the mathematical concepts of 2-, 3-, and 4-fold rotational symmetry. In completing these designs, the students closely followed and applied the engineering design process. In the second semester, a group of three of the original 30 students re-evaluated, re-designed, and fabricated their prototypes from the previous semester. Through this first-year project, these students were responsible for the entire cycle of engineering design, from concept through implementation – a rare opportunity. This paper explores not only the success of one student design project stemming from applying the engineering design process in a first-year engineering program, but also presents from our experience ways in which student learning and development can be enhanced in the first year and continued and augmented beyond the firstyear experience. Introduction and Project Objectives In the fall semester of 2005, 30 students enrolled in a three-credit (two hours lecture; two hours laboratory per week) university course for first-year engineering students (ENGR 1010 “Introduction to Engineering and Technology”) were instructed to complete a guided design project, solving a real problem for a real “customer.” Their charge was to create an instructional device to simulate x-ray diffraction of single crystals. Working with a high school physics teacher (their “customer”), teams of first-year engineering students used the engineering design process to create a device that effectively simulated the phenomenon of x-ray diffraction. X-ray diffraction is the scattering of x-rays by atoms of a crystal into a crystalline lattice pattern. The teacher wanted his students to be able to see and understand how Bragg’s Law, a mathematical definition explaining x-ray diffraction, works. In 1913, Sir W.H. Bragg and his son, W.L. Bragg, derived an equation that validated the fact that real particles exist at the atomic scale. 1, 2 The Bragg’s Law equation can be manipulated to P ge 12750.2 show a direct relationship of the wavelength of the x-ray to the lattice parameter of the object and wavelength of laser and commercially available diffraction film, as shown below. n λx = 2 dx sin (θx) n λl = 2 dl sin (θl) Equation 1 where n is the order of diffraction, and the subscript x represents x-ray and atoms and l represents laser and diffraction films. λx = dx λl = dl Equation 2 Equation 2 shows the ratio of the wavelength of an x-ray (λx) to the distance the atoms are separated (dx) is proportional to the wavelength of a laser (λl) to the distance separating the lines inscribed in a diffraction film. Drawing from the teacher customer’s experience that teaching concepts solely through reading assignments and lectures failed to provide either interest or relevance, he wanted an apparatus that would allow his students to learn this concept through hands-on experimentation. The task for the first-year engineering students was to represent x-ray diffraction using lasers but in a ratio that is mathematically equivalent to using actual x-rays. The main project objective was to design a prototype or demonstration kit that could be used to teach high school students the physics and mathematics behind the theory of x-ray diffraction. To reach this goal, the teams of first-year engineering students implemented the engineering design process 3, 4 to formulate two demonstration kits, one a model for teacher use and the other a model for student use. Applying the Engineering Design Process Following the engineering design process, research about x-ray diffraction was first completed in order for the first-year engineering students to have a good grasp of the topic themselves. The entire class of 30 students first researched the physics of x-ray diffraction of a single crystalline solid and the concept of rotational symmetry of cubic crystals. Following consultation with the teacher customer and the university course instructor, the students generated an extensive list of constraints (project limitations) and criteria (goals for the end-result), an important aspect of the engineering design process. The common specifications for the two kits were as follows: