The field of bioengineering is rapidly changing and expanding to include not only more traditional bioengineering applications (e.g. device-focused areas such as prosthetics, imaging) but also more recent sub-fields and technologies(e.g. more biologically-focused areas such as those enabled by tissue engineering and microfluidics). This rapid change, coupled with the intrinsically interdisciplinary nature of bioengineering, presents a unique challenge to the developers of academic programs, as they need to both select relevant content and strike a balance between depth and breadth. We, the architects of the bioengineering program at the undergraduate-only Franklin W. Olin College of Engineering, which enrolled its first class in 2003, faced a significant additional challenge of our small size (~300 students, ~35 full time faculty, and ~1.5 dedicated bioengineering faculty). Our approach was to create a flexible program that aims to provide students with a strong grounding in both biology and engineering and which leverages Olin’s broad-based foundation in engineering fundamentals and emphasis on hands-on learning experiences. Feedback from alumni/ae, employers and graduate schools regarding our first six graduating classes indicates that an undergraduate education focusing on biology and engineering problem-solving has prepared them well for their current endeavors. The positive response to the program and its graduates confirms that our approach results in graduates who are well-prepared to create the future of bioengineering.
Although lifelong learning is among the most critical skills required of today's engineering graduates, the complex processes through which individuals develop the attitudes, beliefs, and skills of lifelong learners remains unclear. Instructors have only begun to understand the impacts of academic background, institutional climate, and pedagogy on students' development of the motivations and learning strategies characteristic of lifelong learners. In this ongoing mixed-methods investigation, we draw on existing motivation and self-regulated learning theories to examine how undergraduate students at a small private college and a large public university become more self-directed as they progress through the first two years of their engineering programs. Preliminary findings indicate that first-year students at the two institutions report significant differences in their motivations and goal orientations. Students at the small private college express higher intrinsic motivation and learning orientation, and lower external regulation and grade orientation, compared to students at the large public university. The two groups also show differences in their beliefs about individual versus social learning. We briefly discuss how differences in motivations, goals, and beliefs may impact student responses to early program experiences, and require instructors to tailor their approaches to support the needs of emerging lifelong learners.
The purpose of this study is to determine how introductory Project-Based Learning (PjBL) courses affect the self-efficacy of first-year engineering students. Grounded theory is used to analyze twelve interviews with first-year students about their experiences in two PjBL courses, Engineering Design and Physics Laboratory. Data indicate that students' self-efficacy within each course is correlated with the extent to which their course goal perceptions align with those intended by faculty. In Engineering Design, students' recognition of the faculty's intended course goals corresponds to higher levels of self-efficacy. Conversely, in Physics Laboratory, students' low self-efficacy is correlated with a large gap between their perceived and faculty intended course goals. Analysis further reveals that this difference in course goal perceptions may stem from the variations in the courses' contingent scaffolding. Finally, our findings suggest that students' self-efficacy may be further supported by dynamic course scaffolding that allows for an increase in students' autonomy throughout a course.
An asymptotic technique is presented to characterize the bits/symbol achievable on a representative wireless link in a spatially distributed network with active interferers at correlated positions, N receive diversity branches, and linear Minimum-Mean-Square-Error (MMSE) receivers. The models analyzed include analogs to Matern type I and type II networks. It is found that for our network models, with large N, the correlation between interferer positions does not significantly influence the bits/symbol resulting in simple approximations for the data rates achievable in such networks with moderately large numbers of diversity branches.
The engineering student experience is understood to differ for male and female students; gendered interactions affect the development of academic and professional role confidence, as well as engineering identity. The purpose of this session is twofold. First, we aim to introduce participants to concepts of gender schemas, privilege, and identity using a range of interactive activities, including brainstorming and structured discussion. Second, we intend to share information about and obtain feedback on a Gender Discussion Exploration Kit, which the participants will be encouraged to review, use, and share at their home institutions.
In this paper, we present a simple low-voltage MOS cascode current mirror featuring a step response and an output voltage swing comparable to those of a simple mirror and and output resistance comparable to that of a stacked mirror. The proposed mirror operates with an input voltage of Vdiode+VDSsat and can operate on a minimum supply of Vdiode + 2VDSsat. We validate the proposed mirror with a combination of simulated and measured results from a circuit prototyped from transistor arrays fabricated in a 0.5-μm CMOS process through MOSIS.
Promoting a sense of societal connectedness is critical in today’s engineering educational environment. The NAE’s Grand Challenges for Engineering point to broad human concerns — sustainability, health, vulnerability, and joy of living — and human connectivity as the future of engineering problem solving. Engineering studies, however, are often presented in a completely decontextualized manner, with an emphasis on technical content that is free of any human meaning. As a result, students may have difficulty identifying either personal or societal value in their learning tasks. Through their course design, instructors can help students situate themselves and their engineering learning experiences within the larger human system. Studying technologies and technological development within the broader societal context may, in turn, offer significant benefits to student motivation and engagement in learning. In this paper, we report findings from a three-year investigation of the effects of disciplinary integration on student motivation and learning engagement in introductory materials science courses. The quantitative results show that integrating materials science with humanities provides for increased student motivation and cognitive engagement in learning. Compared to students in non-integrated project-based courses, students in integrated project-based courses show higher intrinsic motivation and task value. In addition to these motivational gains, students in the integrated materials science-history course report significantly higher use of critical thinking strategies in their project work, indicating that an emphasis on societal context may help students cognitively engage in their engineering studies. Our findings also indicate that women in the integrated materials-history course report higher intrinsic motivation, task value, self-efficacy, and critical thinking strategy use compared to women in the non-integrated materials course. Overall, our research suggests that putting human contexts at the center of engineering learning can help students build a sense of societal relatedness that promotes better learning.
ABET, ASEE, and the wider engineering community have long acknowledged the potential benefits of interdisciplinary education, including the opportunity to develop non-technical skills such as communication and teamwork while cultivating a broader awareness of the ethical, societal, historical, and environmental impacts of engineering work. Instructors have encountered many challenges in planning and implementing integrated courses, such as the difficulty of coordinating the teaching methods, content, and learning objectives of different academic disciplines in a finite and already overcrowded curriculum. This paper presents the goals, design approach, implementation, and selected outcomes of one integrated project-based course (using Paul Revere and other case studies to integrate materials science with the history of technology) and uses it to discuss the advantages of disciplinary integration, particularly with respect to improved student self-direction and contextual understanding. Assessments administered during and after class suggest that this integrated course successfully engendered high student motivation along with an increase in student aptitudes over the course of the semester without a corresponding loss of discipline-specific knowledge. The implementation of this integrated course and the evaluation of its outcomes are works in progress, and future assessments are being designed to shed additional light upon these issues.
Student development of self-directed learning skills is critical for success in today’s rapidly-changing engineering world. The details of how instructors may best foster engagement in life-long learning, however, are unclear; many educators have struggled to define, implement, and assess lifelong learning in engineering curricula. We present a framework for student autonomy that may serve as a useful curriculum design tool by aiding instructors’ consideration of learner responsibility and development. The model describes lifelong learning as a set of choices over which students may gradually gain control. These areas of learning autonomy include four question categories: why is learning necessary, what should one learn, how should learning occur, and how well is learning achieved. Instructors may create policies in these four areas that produce low or high degrees of learning autonomy. Awareness of the areas of student autonomy may enable course designers to more effectively adopt approaches that meet student needs and foster lifelong learning skill development.
Against a backdrop of compelling societal needs, graduates in science and engineering now must master their disciplines and demonstrate a sophisticated level of cognitive, affective and social development. This has lead a number of national and international commissions on science and engineering to urge educators to re-think the way in which STEM disciplines are taught. We have chosen to “repackage” a traditional undergraduate materials engineering curriculum in a form designed to promote the development of higher-order cognitive skills like self-directed learning and design. Classic metallurgy experiments have been converted to project-based learning experiences where students are put in the role of “designers” of problem solutions and faculty play the role of coaches. These include: designing, prototyping and marketing of a cast metal object; systems designing, building and testing of a fiber optic spectrometer; product improvement of a prosthetic device; design and evaluation of a heat treatment process for roller bearings. Projects were designed to leverage known relationships within the educational psychology literature that enable deeper learning. Evaluation of 36 juniors in a project-based learning course (i.e., the test cohort) against a quasi-control group in traditional engineering courses showed that the test cohort scored significantly higher on two motivation scales shown to be critical components in self-directed learning.
Imagine a course block in which students discuss the cultural implications of 17th century iron working in North America in one hour, and design experiments to examine connections between composition and strength in modern steel padlocks immediately afterward. In the Paul Revere:Tough as Nails course block, students don’t just study materials science and history of technology topics … they experience them. Through a series of readings, discussions, and self designed projects, students explore materials science concepts alongside the social, cultural, and environmental factors that shaped technological and scientific history. Although some formal in class activities are planned, many class sessions are flexible, allowing students to engage in individualized learning approaches. The projects are loosely framed, enabling students to develop key competencies while investigating topics of personal interest and controlling project focus and direction. In this paper, we discuss the processes and motivating factors that led to the initial design and continued development of the Paul Revere: Tough as Nails course block. We describe the philosophical and practical benefits of the course, and we elucidate the important role the course plays in our engineering curriculum.
Harvesting energy from ambient vibration is a promising method for providing a continuous source of power for wireless sensor nodes. However, traditional energy harvesters are often derived from resonant linear oscillators which are capable of providing sufficient output power only if the dominant frequency of input vibrations closely matches the device resonant frequency. The limited scope of such devices has sparked an interest in the use of nonlinear oscillators as mechanisms for broadband energy harvesting. In this study, we investigate the harvesting performance of an electromagnetic harvester sustaining oscillations through the phenomena of magnetic levitation. The nonlinear behavior of the device is effectively modeled by Duffing’s equation, and direct numerical integration confirms the broadband frequency response of the nonlinear harvester. The nonlinear harvester’s power generation capabilities are directly compared to a linear electromagnetic harvester with similar dynamic parameters. Experimental testing shows that the presence of both high and low amplitude solutions for the nonlinear energy harvester results in a tendency for the oscillator to remain in a low energy state for non-harmonic vibration inputs, unless continuous energy impulses are provided. We conclude by considering future applications and improvements for such nonlinear devices.
We present an indoor wireless localization system that is capable of room-level localization based solely on 802.11 network signal strengths and user-supplied training data. Our system naturally gathers dense data in places that users frequent while ignoring unvisited areas. By utilizing users, we create a comprehensive localization system that requires little off-line operation and no access to private locations to train. We have operated the system for over a year with more than 200 users working on a variety of laptops. To encourage use, we have implemented a live map that shows user locations in real-time, allowing for quick and easy friend-finding and lost-laptop recovery abilities. Through the system’s life we have collected over 8,700 training points and performed over 1,000,000 localizations. We find that the system can localize to within 10 meters in 94% of cases.
We have been working on several control and actuation improvements applicable to the design of biomimetic robots and assistive (e.g. prosthetic or orthotic) devices. This paper focuses on the implementation of a joint-level impedance controller for series-elastic actuators that eliminates the use of joint angle sensor information, instead using information from co-located commutation sensors on the back of a brushless motor and a compression sensor on the series elasticity. This approach is both more robust than previous systems and less subject to instabilities due to stiction and backlash.
Examining the perceptions of first-year undergraduates and their instructors can provide insight into these students’ experiences and shed light on the emerging issues of student attrition and lack of preparedness for the workforce. Students’ perceptions about introductory courses have been examined in previous work. On the other hand, as the high rate of university student dropouts has frequently been attributed to the poor quality of teaching in first-year undergraduate courses, this study aims to investigate the perceptions of faculty members instructing first-year undergraduates. Our analysis results in several emergent themes, which include (1) instructor’s beliefs about Project-Based Learning as a teaching practice, (2) instructor’s level of abstraction when talking about students, (3) instructor’s affect towards students, (4) value instructors place on one-on-one interactions with students, (5) instructors’ perceptions of their role in development of student motivation and interest toward their courses, (6) instructors’ perceived ability to impact students, (7) overall teaching goals, and (8) instructors’ motivation towards teaching. From analysis of these emergent themes, there appear to be two distinct instructor groups. These groups, which we will refer to as Personal Coaches and Group Ushers, are observed to have different attitudes and expressed behaviors towards teaching and their students. These findings are important as they shed light into one aspect of undergraduates’ experience, that of faculty support in students’ academic development. The implications of these findings have a profound effect on how we educate the next generation of our national workforce and particularly STEM professionals and we suggest further investigations in this direction. Understanding faculty perceptions is a key step to affect STEM educational reform.
Cells can sense, signal, and organize via mechanical forces. The ability of cells to mechanically sense and respond to the presence of other cells over relatively long distances (e.g., ∼100 μm, or ∼10 cell-diameters) across extracellular matrix (ECM) has been attributed to the strain-hardening behavior of the ECM. In this study, we explore an alternative hypothesis: the fibrous nature of the ECM makes long-range stress transmission possible and provides an important mechanism for long-range cell-cell mechanical signaling. To test this hypothesis, confocal reflectance microscopy was used to develop image-based finite-element models of stress transmission within fibroblast-seeded collagen gels. Models that account for the gel’s fibrous nature were compared with homogenous linear-elastic and strain-hardening models to investigate the mechanisms of stress propagation. Experimentally, cells were observed to compact the collagen gel and align collagen fibers between neighboring cells within 24 h. Finite-element analysis revealed that stresses generated by a centripetally contracting cell boundary are concentrated in the relatively stiff ECM fibers and are propagated farther in a fibrous matrix as compared to homogeneous linear elastic or strain-hardening materials. These results support the hypothesis that ECM fibers, especially aligned ones, play an important role in long-range stress transmission.
Every classroom constructs its own culture through the interactions of all participants, students and instructors. This culture, often covert or invisible, has a direct impact on students’ opportunities to learn. Therefore, it is critical that instructors understand their classrooms’ interaction patterns and their effect on student learning. We suggest that discourse analysis may serve as a tool to enhance instructors’ understanding of their classrooms and to serve as an intervention particularly useful for junior faculty as they are beginning their teaching career. To this end, this paper (1) describes the theoretical foundation of discourse analysis and (2) demonstrates its application, effectiveness, and applicability in STEM classrooms, particularly at the introductory level, the time when students make their first steps in negotiating ‘academic literacies’.
Researchers have developed numerous theories and developmental models to describe self directed learning, lifelong learning, and self-regulated learning. The literature includes a large body of research that illustrates the cognitive, metacognitive, motivational, affective, and behavioral attributes of self-directed learners; the influences of social and physical environment on self-directed learning development; and the roles of self-perceptions, causal orientations,learning conceptions, and demographics in determining certain self-directed learning responses. But how do undergraduate engineering students characterize and critique self-directed learning? This paper evaluates the responses of engineering students to questions regarding the definition of self-direction and the primary positive or negative factors contributing to their self-directed learning experiences. We find that undergraduate students at all levels are able to identify positive and challenging aspects of self-directed environments, and the emergent themes from the qualitative student responses map well onto theoretical frameworks for self-direction and self-regulation. Results are discussed in terms of pedagogical issues to consider when designing curricular experiences aimed at development of self-directed learning competency.
This paper presents a semi-automatic approach to assigning students to project teams for a year-long, industry-sponsored senior capstone course. Successful assignment requires knowl- edge of at least individual project requirements, student skills, student personalities, and student project preferences. This mix of hard skills, soft skills, and interpersonal impres- sions requires human involvement to produce a high-quality assignment. The importance of faculty input often requires that the assignment process be labor- and time-intensive. Our approach attempts to reduce the time required to perform this assignment by selectively automating parts of the task flow. An automated search uses a randomized greedy algorithm combined with local optimizations to explore a large space of solutions. Candidate “good” solutions are then presented to capstone faculty. Criteria such as skill set, student capability, and personality compatibility are applied by human evaluators to reduce the candidate solution set. These candidate solutions are then distributed to small groups of faculty to look for improvements using system-generated tables of options. This approach leverages automation at appropriate stages while keeping the experts—the faculty—involved in the selection process. Our initial implementation has reduced the time needed to select an allocation by about a factor of three over previous manual approaches.
This paper presents some of the challenges, successes, and experiences in designing a new senior engineering capstone program at the Franklin W. Olin College of Engineering. Senior capstone design programs in engineering colleges have evolved over many years and are often modified and reinvented to keep up with the needs of both students and external constituencies. Harvey Mudd College’s Clinic program is one of the largest and longest-running capstone programs in the country that relies heavily on industry sponsors to provide real world problems and funding to execute the projects. For many reasons, and in no small way because of its track record of success, our own capstone course offering is modeled closely upon the Harvey Mudd Clinic program. However, completely importing a well-established program into a different context would be haphazard at best, and would ignore a unique opportunity to retool the program to meet the specific needs of a different college. This paper presents our experience in developing SCOPE, the Senior Consulting Program for Engineering at Olin College, and applying lessons learned from the Clinic Program and other successful capstone programs. We discuss the difficulties such as recruiting industry sponsors for a new and unproven program, developing assessment methodologies, and developing the policies and procedures needed to keep the program running smoothly and in a sustainable fashion. Through this narrative, the authors endeavor to inform other programs that are in need of modification, and educators who find themselves with the opportunity to start a capstone program from the ground up.
The literature consistently reports that students express some degree of discomfort when they are thrown into self-directed learning environments. In this paper, we present the preliminary results of an investigation of the causes of student discomfort in several different self-directed project-based courses. Our results suggest that student motivation and opportunities for the development of deep understanding and transferable skills are important in creating a positive self-directed learning experience. Negative experiences and student discomfort in self-directed environments may stem from problems with self-regulation, low self-perceptions of content learning, lack of personal engagement with the topic, and difficulties related to the social learning environment.
Curriculum development efforts often focus on delineating content within associated constraints: "how can I/we best design a course to cover a set of topics in the time available?". Such an approach is clearly productive, but it can easily lose sight of the people involved and their values. In this interactive session, we explore the importance of being explicit about the people participating in learning experiences. We done this by introducing the use of user-oriented design techniques in curriculum design, and by involving participants in aspects of these techniques.
The importance of "design" in engineering education is well established and a cornerstone of most new engineering curricula as well as accreditation criteria Electrical and computer engineering (ECE) programs view many elements of design in ways similar to other engineering disciplines. However, in some respects other disciplines within engineering, such as Mechanical Engineering (ME), view design in broader terms, and perhaps gain value that electrical and computer engineering educators may miss. This paper describes how design is typically viewed in ECE programs, bow it's viewed in other engineering areas, particularly ME, and suggests some new possibilities for enhancing design education within ECE programs. To illustrate these possibilities, an experimental subject in which entering freshmen build a sophisticated electronic device is described.
Results are presented for the design and testing of an electromagnetic device to convert ambient mechanical vibration into electricity. The design of the device is based on an L-shaped beam structure which is tuned so that the first two (bending) natural frequencies have a (near) two-to-one ratio. This creates an internal resonance or autoparmetic condition that can result in a nonlinear dynamic response to a sinusoidal (base) displacement excitation over an extended frequency range. This is in contrast to single degree-of-freedom, linear-dynamics based vibration harvesters which convert energy in a very narrow frequency band. Representative measurements of displacement and power generated are presented. The problem of fatigue failure in the devices presents limits to their long-term operation.
In some supercomputing environments, users are required to run editing, compiling and data-cleaning tasks on a workstation, and use supercomputers only for jobs that require them. This restriction is intended to improve the performance of the supercomputer, but it causes significant inconvenience for users. In this paper, we examine the workload submitted to the Cray C90 at the San Diego Supercomputer Center, and observe that "workstation jobs" consume less than 20% of the cycles on these machines. We conclude that the cost of supporting these jobs is small compared to the productivity improvement it provides for users.
Metal migration from the thick-film termination can affect not only the electrical characteristics but also the gauge factor or piezoresistive coefficient of thick-film sensors. Four sets of sensors with different ratios were designed to test the influence of the terminal metal migration effects on the gauge factors and resistivity of thick-film resistors. In all the cases, the shortest resistors have a lower gauge factor and a large deviation ofresistances. The longer resistors will have better electrical parameters. SEM (scanning electron microscope) studies showed this interaction at the interface between the terminal and the resistor. The same distance of terminal diffusion is larger for a short resistor than for a longer one.
On the basis of the analysis of all the thick- film design methodologies, the authors designed a test sample on which four different length-over-width ratios of resistors were designed. They found that the length-over-width ratio will substantially affect the gauge factor in some cases, in contrast to prior research. This can be modeled to generate a linear predictive model, The sensors designed on the insulator and the sensors underneath the insulator were also studied in order to simulate the multilayer hybrid technology and study the effects of insulator-resistor-substrate surface interaction. It is demonstrated that design techniques can affect the strain sensitivity of thick-film resistors.
Summary form only given. A wide-band-gap semiconductor, high temperature tolerant microelectronic gas sensor of diamond has been developed for oxygen, hydrogen and CO gas detection. This new device has been fabricated in the form of catalyst-adsorptive oxide(Pt-SnOx )/i(intrinsic)-diamond/p+(doped)diamond, representing a CAIS device structure. The key elements in this structure are SnOx as a gas sensitive layer and PECVD (plasma enhanced chemical vapor deposited) diamond for high temperature operations. The major advantages of using diamond based structures with SnOx for gas sensing are higher operating temperature range, higher gas sensitivity and selectivity, reliable sensing performance in harsh environments, simplicity in fabrication process, compatibility with silicon microfabrication technology, and cost efficiency.