Microplastics
Filtration Device
Why — The Problem & Objective
Microplastics are everywhere now—in our water, our food, and even us. For our APSC 169 project, we wanted to do something about it. Specifically, we looked at how to get these tiny plastic pieces out of lakes without messing up the ecosystem.
We came up with the "Pet Fish." It's a filtration device that looks like a fish so it blends in. The idea is that it swims around (or floats) and filters water through its body, trapping microplastics inside. We wanted something that could work in the real world, not just on paper.
What — Our Outcomes
Design Evolution
Initial Sketch: Early concept focusing on passive water intake mechanisms.
Filter Diagram: Detailed cross-section of the mesh layering system.
System Analysis: Final flow loop design ensuring continuous filtration.
The "Pet Fish" Device
Our final concept: a fish-shaped filter that blends into the lake environment.
We moved from a static filter design to a mobile "fish" concept to increase the volume of water treated. This decision was driven by our flow rate calculations, which showed that a stationary unit would be too passive to be effective in a large lake.
Here's what we actually did over the semester:
- Drew a ton of sketches (some were terrible, some were okay)
- Built CAD models in Fusion 360
- Tested materials to see what wouldn't rot underwater
- 3D printed a prototype to see if it fit together
- Figured out how much it would cost and what could go wrong
How — My Process
Key Contributions
- Material Research & TestingI spent a lot of time researching materials. We needed something that wouldn't break down and add MORE plastic to the water. We looked at recycled aluminum and stainless steel.
- Risk AnalysisWe had to think about everything that could go wrong—like what if a real fish tries to eat our robot fish? Or what if it gets clogged?
- Design IterationWe went through a few designs. First it was just a sketch, then a diagram of the filter, and finally a 3D model.
Tools Deployed
Challenges & Solutions
Material Degradation
Challenge: Materials degrading underwater or releasing microplastics themselves.
Solution: We looked at how materials handle being underwater for a long time. We didn't want to use something that would rust or fall apart after a week.
Flow Rate vs. Filtration
Challenge: Balancing flow rate with filtration effectiveness without clogging.
Solution: If the filter is too tight, water can't get through. If it's too loose, the plastic gets through. We had to find a balance (around 100 microns) that worked.