Oct 17, 2024
Junk Jenius is a plastic bottle recycling machine designed for my college campus to encourage and optimize recycling by automating the cutting, draining, and crushing of plastic bottles in one motion. By combining these steps in a single engaging system, it reduces common barriers to recycling, like leftover liquids and the hassle of manual preparation. I collaborated with three other engineering and business students on this project, with a main focus that we were creating a product that met market and manufacturing needs.
In addition to contributing to ideation and problem solving during development, my contribution was developing all digital (CAD) and physical (machine-shop) prototypes
=> Awarded Best Prototype Award at the Carnegie Mellon Engineering Expo.
Project Goal: Compact plastic bottles in an engaging way to reduce volume, drain residual liquids, and motivate people to recycle.
Specifically, we will:
1. Simplify disposal process for the user
2. Reduce waste volume, optimizing transportation and disposal, and
3. Motivate users to recycle by improving engagement.
Why: Secondary research confirmed high plastic bottle usage and low recycling rates on campus.
User Studies: Finding pain points through competitor analysis
To understand the biggest barriers to recycling, my team conducted a competitor study on a compacting Joseph Joseph trash can by deconstructing, documenting, and analyzing its mechanisms, then doing user tests in a real college kitchen over 48 hours.
Pain Points in Competitor Product: high learning curve, not structurally sound (parts broke off during normal use), manual operation => about as effective as just using your hands.
Positives in Competitor Product: users appreciated the novelty of the product (it's fun to crush stuff!) and the improved hygiene (don't need to touch waste).
Takeaways:
Our solution should be automatic, easy to use, and durable enough to actually compact. Other key ideas: integrating a liquid drainage system, ensuring a one-button operation for ease of use, and incorporating the satisfaction of crushing stuff.
Competitor Study - Joseph Joseph Intelligent Waste Titan Trash Can Compactor:
From Proof of Concept to Lo-Fi Prototypes, to CAD, Build, & Analysis
1) Crush! | The linear actuator was selected for its size, range, and force, and comparisons with our system requirements. For proof of concept, I hooked it up via a breadboard and 3-way switch, testing with empty bottles, an old PVC pipe, and very rudimentary mounting… it worked!
2) Planning | When my team had a disagreement on the product layout, I quickly made some rough sketches, CAD, and a lo-fi prototype of the vertical layout to find its pros and cons. We chose the horizontal layout, but now with a modified slant to aid drainage/crushing.
3) Build/Test | I built the rest of the prototype by manually machining scrap material in the woodshop/machine shop, optimizing sizing and placement by going back and forth between CAD, prototype, and testing. For example, the shape of the blade was refined such that the blade can pierce the bottle without getting stuck when it retracts.
4) Analysis | Safety and durability was ensured via FBDs, hand calcs, and FEA stress analysis, particularly on the weakest point in the machine and on the linear actuator mounts.
Additional Safety Measures: by default, the machine is "off" and only operates as long as the user holds the switch down. Also, the only user-facing components are the bottle insertion chute, the operation switch, and the hold that the crushed bottle drops out of. Everything else (moving components, blades, crushing chamber) is covered. So, we knew it was safe to allow anyone to use.
Final Product: The Junk Jenius Water Bottle Crusher - Cut, Drain and Crush Bottles, All In One Motion!
Our final design successfully met our goals of being functional, durable, simple, and user-friendly.
As a final touch, I designed a final mockup for the Expo, incorporating Pittsburgh iconography to resonate with our local campus users. The blade holder is shaped like Pittsburgh's iconic red bus, holding the blades as a "snowplow" that will crash through and destroy the water bottles. As the mechanism operates, the bus zooms through Pittsburgh’s iconic bridges (aka the linear actuator mounts), while the outer frame mirrors the city's hilly skyline. The front wall is constructed from clear acrylic, allowing users to watch the satisfying destruction.
We showcased this interactive prototype and mockup during the 2024 CMU Engineering Design Expo, receiving a lot of positive reactions! In addition to our group's pitch and explanation of the project, we gave live demos of the machine actually crushing a variety of bottles and allowed people to try it themselves too. By popular vote amongst attendees, our project was awarded "Best Prototype," validating its creativity, functionality, and broad appeal. It was well-received during user testing, with feedback highlighting its creativity and interactivity with users, and functional potential to enhance recycling rates in public spaces.
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Reflection:
As my final engineering capstone project, this was a very exciting experience. My team and I had a great dynamic with a collaborative and respectful division of work. I was very proud of my contributions in CAD design, prototyping, and general teamwork. The most satisfying part was seeing our concept evolve into a functional project that not only addressed a real-world problem we saw around us, but brought joy to its users. I think it resonated with our audience because it was relevant to them and it was fun. Because our school is in Pittsburgh, everyone could relate to the iconic local elements. The Pittsburgh-inspired aesthetic design and interactive functionality helped make the machine not just practical but also enjoyable to use. If we had more time, I would probably want to focus on further developing the prototype's visuals to match the mockups, include more interactive elements like displaying how many bottles it has recycled, and streamlining the manufacturing process to reduce material waste. But all in all, given our time and resource constraints, I am extremely happy with the final product!
