Sidewalk Power Generator
Description
This project was completed as part of my freshman Introduction to Engineering class in the spring of 2011. Our group was tasked to build any prototype we wanted and a GUI modeling the prototype with a $100 budget. The motivation behind this project was to create and build a solution to a problem in the world. With the Notre Dame campus aiming to become more Earth-friendly, it was decided to focus our project on clean energy production. We ended up choosing to build a sidewalk power generator prototype and a GUI modeling how much energy we would produce if implemented in different cities.
Individual Contributions
My personal contributions to this project involved sketching, coming up with and deciding on which idea to prototype, ensuring communication between the software and prototype groups, and helping to build the prototype.
Approach
The entire class began this project by generating and researching ideas to complete a project on and then voting for the best ideas. Groups then formed based on which idea students liked best. My idea of a sidewalk power generator was produced by seeing a video about a piezoelectric dance floor in Europe. I became fascinated with the idea of converting kinetic energy into electricity. I thought this would be good technology for use in sidewalks, but $100 did not provide enough money for piezoelectric tech. I tried to then brainstorm all the ways energy could be produced from a sidewalk.Thinking of the motion of a train wheel brought me to an idea where we could turn a wheel that could turn a motor to produce electricity. After further fleshing out the idea within the group, the motion of someone stepping down on something could turn the wheel which would turn the kinetic energy into electricity. An early sketch is shown below.
Early Sketch of Idea
Springs would be used to store the energy and allow the wheel to make a full rotation so that the step platform could return to the original position. A multimeter would be used to track how much energy we could produce. The final prototype we produced is shown below.
Final Prototype
This final prototype was built after some iteration. We determined our stepping area needed more support and adding some support blocks improved this. We also ensured our springs were going to stay in place with washers screwed down after some stability issues appeared. A mount on the gear was needed instead of attaching our piston rod directly to the gear system used to turn the motor because of energy transfer problems.
There was also a GUI constructed that could model the predicted performance of the project based on the weight of a person and efficiency factor. Another feature of the GUI showed predicted electrical outputs from various cities in the world. With a successful project, we were able to conclude that it would take many of the constructed models to create a significant electrical output. Nevertheless, implementation of the project to create a clean energy source is definitely possible. We were able to successfully prove our concept by using the prototype and remained under budget by around $50 as seen below.
Results
We were able to successfully generate an idea to solve a clean energy problem in the world and take that idea from paper sketches to a physical prototype. The project was successful in proving our concept and remaining under budget. Further iterations would need to be made to make this commercially viable and piezoelectric would likely be the most space and cost efficient technology to use in future prototypes.
