An Initial Exploration of the Perspectives and Experiences of Diverse Learners\u27 Acceptance of Online Educational Engineering Games as Learning Tools in the Classroom

This Work-In-Progress falls within the research category of study and, focuses on the experiences and perceptions of first- and second year engineering students when using an online engineering game that was designed to enhance understanding of statics concepts. Technology and online games are increasingly being used in engineering education to help students gain competencies in technical domains in the engineering field. Less is known about the way that these online games are designed and incorporated into the classroom environment and how these factors can ignite inequitable perspectives and experiences among engineering students. Also, little if any work that combines the TAM model and intersectionality of race and gender in engineering education has been done, though several studies have been modified to account for gender or race. This study expands upon the Technology Acceptance Model (TAM) by exploring perspectives of intersectional groups (defined as women of color who are engineering students). A Mixed Method Sequential Exploratory Research Design approach was used that extends the TAM model. Students were asked to play the engineering educational game, complete an open-ended questionnaire and then to participate in a focus group. Early findings suggest that while many students were open to learning to use the game and recommended inclusion of online engineering educational games as learning tools in classrooms, only a few indicated that they would use this tool to prepare for exams or technical job interviews. Some of the main themes identified in this study included unintended perpetuation of inequality through bias in favor of students who enjoyed competition-based learning and assessment of knowledge, and bias for students having prior experience in playing online games. Competition-based assessment related to presumed learning of course content enhanced student anxiety and feelings of intimidation and led to some students seeking to “game the game” versus learning the material, in efforts to achieve grade goals. Other students associated use of the game and the classroom weighted grading with intense stress that led them to prematurely stop the use of the engineering tool. Initial findings indicate that both game design and how technology is incorporated into the grading and testing of learning outcomes, influence student perceptions of the technology’s usefulness and ultimately the acceptance of the online game as a learning tool. Results also point to the need to explore how the crediting and assessment of students’ performance and learning gains in these types of games could yield inequitable experiences in these types of courses

Rutgers University Research Experience For Teachers In Engineering: Preliminary Findings

In addressing the nation’s need for a more technologically-literate society, the Rutgers University Research Experience for Teachers in Engineering (RU RET-E) is designed to: (1) engage middle and high school math and science teachers in innovative “green” engineering research during the summer, and (2) support teachers in integrating their research experiences into their academic year, precollege classrooms. The current paper addresses the following two questions: (1) To what extent did RU RET-E impact participants? and (2) To what extent did participants implement resulting lesson plans? During the 2011 summer, seventeen math and science teachers (RU RET-E Fellows) engaged in “green” research alongside faculty and graduate students. Teachers were required to apply to the program in pairs as one math and one science teacher from the same school. The rationale was that the team would develop interdisciplinary lessons and that teachers would have a colleague at their school who shared the same experience as supports during the school year. The paper provides an overview of the summer experiences and the academic year follow-up activities. Data from the pre- and post-surveys and follow-up questionnaire about lesson implementation are presented. Preliminary data evidences that RU RET-E was successful in enhancing teachers’ understanding of engineering and supporting them as they designed lessons for their precollege classrooms. Most notably, teachers’ confidence in their ability to define engineering, describe what engineers do, generate challenging problems for advanced students and integrate engineering into their curriculum increased significantly.

An Analytical Model for the Effective Dielectric Constant of a 0-3-0 Composite

An analytical expression for prediction of the effective dielectric constant of a three phase 0-3-0 ferroelectric composite is presented. The analytical results are verified with the experimental results from Nan et al. (2002, "Three-Phase Magnetoelectric Composite of Piezoelectric Ceramics, Rare-Earth Iron Alloys, and Polymer," Appl. Phys. Lett., 81(20), p. 3831). The analytical model is extended to include the shape of a third phase inclusion to examine the influence of the shape (of the inclusion) on the effective dielectric constant of the composite. The dielectric constant increases as much as seven times when the aspect ratio of the conducting inclusion particle is increased from 1 (sphere) to 10 (spheroid). A comparison of the analytical predictions with the experimental values, which indicate that the increase in aspect ratio of the inclusions has a significant effect on the overall dielectric constant of the composite

Utilising Nonlinear Air Damping as a Soft Mechanical Stopper for MEMS Vibration Energy Harvesting

This paper reports on the theory and experimental verification of utilising air damping as a soft stopper mechanism for piezoelectric vibration energy harvesting to enhance shock resistance. Experiments to characterise device responsiveness under various vibration conditions were performed at different air pressure levels, and a dimensionless model was constructed with nonlinear damping terms included to model PVEH response. The relationship between the quadratic damping coefficient ζ n and air pressure is empirically established, and an optimal pressure level is calculated to trade off harvestable energy and device robustness for specific environmental conditions

Figure of merit comparison of PP-based electret and PVDF-based piezoelectric polymer energy harvesters

The harvesting of mechanical strain and kinetic energy has received great attention over the past two decades in order to power wireless electronic components such as those used in passive and active monitoring applications. Piezoelectric ceramics, such as PZT (lead zirconate titanate), constitute the most commonly used electromechanical interface in vibration energy harvesters. However, there are applications in which piezoelectric ceramics cannot be used due to their low allowable curvature and brittle nature. Soft polymer PVDF (polyvinylidene fluoride) is arguably the most popular non-ceramic soft piezoelectric energy harvester material for such scenarios. Another type of polymer that has received less attention is PP (polypropylene) for electret-based energy harvesting using the thickness mode (33-mode). This work presents figure of merit comparison of PP versus PVDF for off-resonant energy harvesting in thickness mode operation, revealing substantial advantage of PP over PVDF. For thickness-mode energy harvesting scenarios (e.g. dynamic compression) at reasonable ambient vibration frequencies, the figure of merit for the maximum power output is proportional to the square of the effective piezoelectric strain constant divided by the effective permittivity constant. Under optimal conditions and for the same volume, it is shown that PP can generate more than two orders of magnitude larger electrical power as compared to PVDF due to the larger effective piezoelectric strain constant and lower permittivity of the former

Maximum Power of Thermally and Electrically Coupled Thermoelectric Generators

In a recent work, we have reported a study on the figure of merit of a thermoelectric system composed by thermoelectric generators connected electrically and thermally in different configurations. In this work, we are interested in analyzing the output power delivered by a thermoelectric system for different arrays of thermoelectric materials in each configuration. Our study shows the impact of the array of thermoelectric materials in the output power of the composite system. We evaluate numerically the corresponding maximum output power for each configuration and determine the optimum array and configuration for maximum power. We compare our results with other recently reported studies

Rectifying the output of vibrational piezoelectric energy harvester using quantum dots

Piezoelectric energy harvester scavenges mechanical vibrations and generates electricity. Researchers have strived to optimize the electromechanical structures and to design necessary external power management circuits, aiming to deliver high power and rectified outputs ready for serving as batteries. Complex deformation of the mechanical structure results in charges with opposite polarities appearing on same surface, leading to current loss in the attached metal electrode. External power management circuits such as rectifiers comprise diodes that consume power and have undesirable forward bias. To address the above issues, we devise a novel integrated piezoelectric energy harvesting device that is structured by stacking a layer of quantum dots (QDs) and a layer of piezoelectric material. We find that the QD can rectify electrical charges generated from the piezoelectric material because of its adaptable conductance to the electrochemical potentials of both sides of the QDs layer, so that electrical current causing energy loss on the same surface of the piezoelectric material can be minimized. The QDs layer has the potential to replace external rectification circuits providing a much more compact and less power-consumption solution

Resonant wave energy harvester based on dielectric elastomer generator

Dielectric elastomer generators (DEGs) are a class of capacitive solid-state devices that employ highly stretchable dielectrics and conductors to convert mechanical energy into high-voltage direct-current electricity. Their promising performance in terms of convertible energy and power density has been mostly proven in quasi-static experimental tests with prescribed deformation. However, the assessment of their ability in harvesting energy from a dynamic oscillating source of mechanical energy is crucial to demonstrate their effectiveness in practical applications. This paper reports a first demonstration of a DEG system that is able to convert the oscillating energy carried by water waves into electricity. A DEG prototype is built using a commercial polyacrylate film (VHB 4905 by 3M) and an experimental campaign is conducted in a wave-flume facility, i.e. an artificial basin that makes it possible to generate programmed small-scale waves at different frequencies and amplitudes. In resonant conditions, the designed system demonstrates the delivery of a maximum of 0.87 W of electrical power output and 0.64 J energy generated per cycle, with corresponding densities per unit mass of dielectric elastomer of 197 W kg-1 and 145 J kg-1. Additionally, a notable maximum fraction of 18% of the input wave energy is converted into electricity. The presented results provide a promising demonstration of the operation and effectiveness of ocean wave energy converters based on elastic capacitive generators

Miniaturized supercapacitors: key materials and structures towards autonomous and sustainable devices and systems

© 2016 The Authors Supercapacitors (SCs) are playing a key role for the development of self-powered and self-sustaining integrated systems for different fields ranging from remote sensing, robotics and medical devices. SC miniaturization and integration into more complex systems that include energy harvesters and functional devices are valuable strategies that address system autonomy. Here, we discuss about novel SC fabrication and integration approaches. Specifically, we report about the results of interdisciplinary activities on the development of thin, flexible SCs by an additive technology based on Supersonic Cluster Beam Deposition (SCBD) to be implemented into supercapacitive electrolyte gated transistors and supercapacitive microbial fuel cells. Such systems integrate at materials level the specific functions of devices, like electric switch or energy harvesting with the reversible energy storage capability. These studies might open new frontiers for the development and application of new multifunction-energy storage elements