Senior Design
The challenge | Every engineering student at CU ends their undergraduate education with a capstone project. This project is meant to give everyone the experience of being part of a complete engineering project from start to finish. But, this means more than the technical design and manufacture. This project forces everyone to face group dynamics, ambiguity, leadership and followership, accountability and professionalism, and communication of engineering design.
Business Acumen | Most teams get a project from an industry partner and must navigate the client relationship. I chose to participate in a smaller section of senior design called "engineering for social innovation." The teams in this section of the course started even earlier in the design process. We created our own problem statement, and explored possible solutions to fill that need. We focused on the problems that don't get much engineering attention, such as energy or clean water in low-income countries. We competed in the CU Boulder New Venture Challenge for startup funding. My role in the project was project manager.
Our Project | We also had to create a rigorously documented engineering design, and then manufacture a functional prototype to present at the design expo. The product we ended up creating is an under-sink water system with a mini electricity generating turbine, water filter, water sensors, and a simple user interface. We targeted this product for a population like Pretoria, South Africa. In Pretoria there is a consistent supply of water to many homes, but the quality is not trusted and bottled water is used for most all drinking water. Electricity is intermittent and expensive. People want water quality they can trust. We thought a system such as ours could reduce plastic waste and provide water at a much lower cost than bottled water.
Copy of 2019100400.PDFEverything began with an arduous research process. We explored the field of water filtration and sensing, something none of us had any expertise in before. We also explored the design of turbines, and chose to create a tesla-style turbine to generate electricity from low-pressure piped water.
After the first semester we presented our complete stack of CAD drawings and our plans for manufacture of the product. To left, you can see one of these CAD drawings.
Learning Leadership Managing an open-ended, semester long research and design process being conducted by a team of five multi-cultural engineers, who were strangers before the project began, was a leadership challenge beyond any I had faced before. I gained a massive newfound appreciation for the importance of having a shared "vision." I mean down to the details of how we fill out the title block on a CAD drawing, specifying what file format a document should be in, or the resolution of a rendered image so it looks good printed. But even more important are the high level goals. What is the specific need we are trying to fill for our user? What exactly does the product need to do? What does it mean to rigorously justify an engineering design? What depth of research? What rigor/accuracy do the mathematical models and calculations need to have? How much time and effort are we putting into this, and what quality of a design are we aiming for? What is accountability, and what is completing an assigned task on time mean?
All of these questions challenged us throughout the semester, and I learned what it means to create specifications, expectations, and communications that people can understand, find motivating and act on.
Manufacturing was more straightforward than design. But, it was also more sensitive to delays from missing materials or incorrectly machined parts.
Left: image of the completed disc pack of the tesla-turbine. These discs spun at a 1000-3000 RPM as water flowed over them.
Right: image showing the layout of the electronics box. This held the battery, charge controller, and sensors. Wire management is important.
There were so many considerations to make this a refined product. What are the standard under-sink pipe connections in South Africa? How much information do people want from their user interface? How would the system be sturdily-mounted? What is the typical water flow and pressure in South Africa, and how much electricity would we need to produce to be useful?
Right: our prototype mounted for presentation at Expo.
Copy of Tap46 Expo Poster.pdfWe were exhausted by the end. Presenting a clean and functional product was a sweet reward.
Design for the 90% The biggest thing I learned from trying to make this particular product was that there is a reason access to clean drinking water is still an issue around the world. It is a much harder problem than it seems, and the technology to do it affordably at the household level does not exist. For example, the best sensor that exists for continually measuring water quality, and costs under $100,000, is a turbidimeter, which measures total particulate matter - a weak proxy for bacteria and heavy metals. There is an exciting effort at CU Boulder by Emily Bedel to create an IOT-style bacteria meter. Additionally, water filters that are effective at removing the important contaminants (microbes and heavy metals) require high pressure and cost more than a typical family in a low-income country could afford. Lifestraws and similar products are effective, but require time for the water to drip through. Unfortunately, a product like ours would require significantly more R&D to be a marketable product.