Proceedings of the Spring KGCOE Multi-Disciplinary Engineering Design Conferencepage 1

Proceedings of the Spring KGCOE Multi-Disciplinary Engineering Design ConferencePage 1

Project Number: 05903

Proceedings of the Spring KGCOE Multi-Disciplinary Engineering Design ConferencePage 1

Design of Engineering Related Teaching Aids for Middle and High School Students

Lisa Bonanno – Electrical Engineer / Ryan Carr – Industrial Engineer
L Jeffrey Kelly – Mechanical Engineer / Joel Lomnick – Electrical Engineer

Proceedings of the Spring KGCOE Multi-Disciplinary Engineering Design ConferencePage 1

Abstract

The mission of this project is to promote an interest in engineering of middle and high school students with the help of several engineering related teaching aids. Design and build a Traveling Engineering Mobile Exhibit – Develop a series of engineering and science related experiments and training aids aimed at middle and high school students to raise their interest and awareness of different fields of engineering. It is important that we emphasize the multidisciplinary opportunities in engineering.

introduction

Four different teaching aids were developed, representing a variety of engineering concepts and disciplines. It is necessary that this project is to interest middle and high school students, women in particular, in pursuing studies, and even careers in engineering and related technology fields. The projects cover concepts found in electrical engineering, mechanical engineering, industrial engineering, and bioengineering.

ELECTROCARDIOGRAPH

One of the requirements of this project was to include a biomedical engineering related teaching aid. This field of engineering is a somewhat unconventional type that many have not heard of; therefore exposure to this application of engineering is great for the young people participating in the program. Due to the fact that many women are interested in biology, this teaching aid is inclined to attract women to the field of engineering. This teaching aid is geared towards high school students, however can be used with middle school students.

An electrocardiogram (ECG) applies electrical engineering towards gathering data on the health of the human heart. The ECG allows safe, fast, and cost effective testing for the characterization of various heart diseases and irregularities. This modern day invention has widespread use among doctors, hospital technicians, and emergency response teams. This teaching aid takes something that is familiar to everyone; the human heart beat, and illustrates how engineering can be applied to help collect information about it.

The kit consists of an analog circuit board, electrodes, Data Acquisition (DAQ) unit, batteries, a screwdriver, a laptop computer, and an instruction manual. Due to battery power this kit can be used anywhere dry. Background information is provided to the students introducing the concepts of electrical conduction in the body and anatomy and physiology of the heart. The students will go through the activity of connecting the electrodes to themselves and viewing their own heart wave on the computer real time.

This waveform is called an Electrocardiograph (ECG) and has three distinct sections: the P wave, QRS complex, and the T wave. Each section of the wave corresponds to a different stage in the contraction of the heart. This reinforces the information learned about the anatomy and physiology of the heart.

Different activities can be completed to examine how the ECG signal and heart rate changes with caffeine, while holding one’s breathe, and while hyperventilating. The engineers’ job is taught through discussing what is needed by the system to get a readable output signal.

Activity / Expected Outcome / Lesson Learned
Measure ECG signal while hyperventalating / Heart rate will increase / Heart must pump faster to exchange oxygen and carbon dioxide with cells in the rest of the body
Measure ECG signal of student while holding in his/her breath. / Amplitude of QRS complex will decrease / Ventricles are not working as hard to pump blood, because little gas exchange is occurring
Measure ECG signal of student after some physical activity. / Heart rate will increase / Heart must pump faster during physical activity to exchange gas with muscles.
Turn potentiometer to change gain of amplification stage in ECG circuit. / If turn left: amplitude of ECG increases.
If turn right: amplitude of ECG decreases. / By changing the resistance values external to the differential amplifier the gain value changes.
The white electrode cable, or Right Leg Drive, is removed from the arm / Noise may be added to the signal. (Depending on how much noise is in room of operation) / The right leg drive reduces noise in the ECG circuit
Switch the green electrode cable to the right and the black to the left. / The ECG signal will invert. / The differential amplifier in the circuit is subtracting the potential of the black electrode cable from the green electrode cable.

Figure 1: ECG Activities Summary

The requirements of the circuit include: 1) safety for the student/patient, circuit, and computer, 2) amplification of the small signal collected by the electrodes at the surface of the skin, and 3) filtering of 60Hz as well as other frequency noise. These concepts are taught by a provided power point presentation as well as reinforced through sample activities described in Figure 1. Finally the students will learn about the importance of engineering in the medical diagnosis of heart diseases. Sample ECG waveforms will be provided that illustrate how technicians can diagnose patients based on their ECG waveform.

FACTORY SIMULATION

Arena Simulation – Wonka Chocolate Bar Production Line

The simulation portion of this project that portrays the actual production process for Willy Wonka Chocolate Bar was constructed in order to display a few aspects of Industrial and Systems Engineering. The main aspects of Industrial and Systems Engineering that are captured through this model are the improvement of designed systems and making a system as efficient as possible. The construction of simulations is a vital tool in industry.

The Willy Wonka Chocolate Bar simulation will be able to do just that because the students will be able to visually see what takes place along an assembly line and what can be done to improve the system to make it more efficient.

The students using this program will be able to see first-hand what is taking place in this simulation and by playing with the components of the system, figure out which areas have the biggest impact on the performance of the assembly line.

The Willy Wonka Chocolate Bar simulation was constructed in using Arena software, a program produced by Rockwell Automation. The constructed model will contain the actual chocolate making process and give the students an idea of how products move along an assembly line. The assembly line contains nine different workstations that include machines and workers. Each workstation is unique and essential in the production of the Willy Wonka Chocolate Bar. The assembly line covers the entire production process beginning at the introduction of the cocoa beans all the way to where they are shipped out of the factory to customers. The simulation model contains a great deal of advanced automation that will allow the students to actually see what is happening along the production line and which stations seem to have the biggest affect on the output of the system.

By interacting with this program and changing a few of the components of the assembly line, students will be able to eventually discover that the bottleneck station is what decides how many parts your line will produce. The students will then in essence be doing exactly what an Industrial Engineer in the real world would be doing by locating the bottleneck in the system and finding a way to improve it in the most efficient way.

Student Interaction with Arena Simulation

The main intention behind creating a simulation of an assembly line was to give students a chance to interact with some of the tools that engineers actually use in the field today. The Willy Wonka Chocolate Bar production Line was developed with this thought in mind and a stimulating activity was developed along with the model to give the students a chance to utilize and manipulate the simulation.

The activity manual created for the Arena simulation requires the teacher of the class to split his/her students into two groups. This aspect of the activity will quickly grab the attention of the students if they know that there may be a prize at stake. The two groups will each have a few minutes to use the program and change a few of the resources in the program. These resources are assembly line workers, a process machines, and forklifts. The students will have the ability to add workers and machines to any of the nine workstations along the entire Willy Wonka Chocolate Bar production Line.

The goal of changing the resources in the model is to try and get the most Willy Wonka Chocolate Bar bars through the line in one day. This time period will already be specified in the simulations running parameters. After each group has had a chance to use the program and see what is actually going on, the competition will begin.

In the competition, each group will be given $100,000 to try and produce the most amount of money possible for the Willy Wonka Chocolate Bar Company. The students will then be told that adding a worker will cost them $50,000, adding a machine will cost them $100,000, and a forklift will cost them $50,000. Thus, they will only be able to add one machine, or two workers, or two forklifts. They also have the option of keeping some of the money to see if they can produce the most money for Willy Wonka Chocolate. The finished Willy Wonka Chocolate Bars that are coming off the line will each be worth $5 so the more you produce, the more money you are making. Once the students choose the changes that they want to make for their group, they will input these modifications into the simulations user interface and run the program. Once the program is finished, they will then be able to see how many Wonka bars they were able to produce, how much money they made, and what the affects of their changes were to the overall throughput of the system. The winning group will then be awarded a prize, such as a Wonka candy bar, at the discretion of the teacher or coordinator.

Once the competition is completed, the teacher/coordinator will have a chance to discuss what actually takes place in an assembly line and what changes make the biggest affects to the throughput of the assembly line. The background information needed for this part of the presentation will be provided in the activity packet and the teacher will be able to convey some fundamental components of an assembly line, which are used around the world today.

MECHANICAL WORKSTATION

With a Mechanical Engineer on the team, a teaching aid geared toward Mechanical Engineering was developed. The goal of this project was to develop and gain students interest in Mechanical Engineering while teaching them the possibilities within such a broad discipline.

The kit consists of a vibrating beam experiment and a simple pendulum both designed to enhance student’s experience and interaction with the program. The vibrating beam consist of two beams, both excited by a motor with an off balance weight, while one will be fitted with a dampening beam. The student will be able to see first hand the effects of dampening vibrations. The pendulum is approximately 18 inches long with an adjustable weight, weighing 500 g.

Mechanical Engineering being very broad subject the students are taught various different avenues that one can explore as a mechanical engineer. A power point presentation is included on the supplied laptop and in CD form. Relating to the vibrating beam the student will be exposed to a video clip of the TacomaNarrowsBridge and how it destroyed its self through excessive vibration.

THE THEREMIN

This teaching aid explores the musical applications of electrical engineering. This field of engineering is familiar to those who have used, seen, or heard of electronic instruments such as pianos and guitars. Many young women (and men) are interested in musical instruments and express those interests in things such as school bands. This teaching aid will introduce a not so well known musical instrument called the Theremin. This teaching aid is appealing to students of all ages. The internal circuitry is complicated, but the functionality of the Theremin is simple to explain, understand, and use.

The Theremin is unique in that it is played like a musical instrument without being touched. Two antennas protrude from the Theremin; one controlling pitch, and the other controlling volume. There are also knobs that can alter volume, pitch, waveform, and brightness of the sound frequencies. To hear sound from the Theremin, there needs to be either a speaker, or headphone connection. There is also an adapter included to power the Theremin.

For a workshop, a brief discussion about electronics and “good” forms of vibrations, such as musical instruments, will lead into the introduction of the Theremin. An instructional video, included with the Theremin kit, can show Theremin expert, Lydia Kavina, teaching lessons in how to properly tune and play the Theremin. Afterwards, the students will be able to experiment with the Theremin by performing simple exercises using their hands. Students will be moving their hands over the vertical and horizontal antennas to show the effects of their bodies reacting to the Theremin circuitry. Students may also vary sounds by changing the tuning knobs, thus hearing high pitch instruments (violin-like sounds), or low pitch instruments (horn-like sounds).

Those interested in more information regarding the mathematics behind the Theremin can use an oscilloscope (virtual one’s are available online), and/or create a simple circuit consisting of an inductor (antenna coil) in series with two capacitors in parallel; one standard capacitor (antenna coil) and one a variable capacitor (a human hand). There are also several websites available that thoroughly explain how to build your own simple Theremin model.

RESULTS - Demonstration Workshop with Local Girl Scouts

On April 30th the senior design team conducted am engineering workshop with the local Girl Scouts. Thirty girls and four adult leaders from five different troops were in attendance. The day’s activities began at 9 am with a lunch break around noon, lasting until 3 pm. The team gave four presentations each approximately an hour long. Overall the workshop was very successful with thanks from Alicia Velasco the Director of Program and Adult Development. Surveys were given to both the girls and the adults at the beginning of the day and the end. This data was complied to yield a feeling of the effectiveness of the Engineering Workshop.

Results were very good. We asked the girls to give feedback on the interest of a particular project. The feedback included topics such as the educational value, how long each presentation was, and the technical level of each demonstration. The majority of the girls that took a survey felt that each of the projects was moderately interested in the subject matter being presented. It was expressed that the educational value was better far better than average, just shy of a score of best. The girls did feel that, on average the presentations given were on the long side, while they also felt that the technical level was slightly higher than expected. One observation taken from the workshop was that the girl scouts were very attentive and willing to interact with the senior design team, not to mention that their knowledge exceeded the team’s expectations.

It was noted that some of the girls replied to the survey saying that their mother made them attend. Those same girls also responded negatively in the pre-survey. To our success, again those same girls gave meaningful and positive remarks on the post-survey given. The team was very excited to see such result and would be willing to say that our prototype demonstration was a success.

LESSONS LEARNED

The demonstration for the local girl scouts was intended to be given in four small groups that would rotate throughout the day. Due to the facility requirements and our presentation requirements we were forced to give our presentations to the entire group of girls one at a time. Although the results are favorable, we feel that they could have been much improved by splitting the girls into four rotating groups. This would give the girls a more interactive, hands-on experience.