YOU CAN BUILD A WALL OF LIQUID MAGNET THAT DRAWS ANIMATIONS IN MID-AIR
252 electromagnets move black magnetic liquid up against gravity to draw animations in mid-air — the biggest open-source ferrofluid display in the world.
DisplaysOpen-hardware
- difficulty
- ●●●●●
- time
- months, not weekends
- license
- GPL-3.0
- repo
- repo ACTIVE152 stars
●●●●● · months, not weekends · GPL-3.0 · 152 stars · repo ACTIVE
WHAT YOU’LL NEED
- 3D printer + filament — printable parts — files are in the repo
- Dev board / microcontroller — runs the project firmware
Partner
COMPAREE VERDICT
Fetch is a genuinely impressive build: 252 individually controlled electromagnets arranged in a 12×21 matrix pull ferrofluid droplets up against gravity to animate pixel art and a functional clock. It is the largest open-source ferrofluid display documented to date, and the technical ambition shows. The firmware is here, the CAD is here, and the result is visually stunning. But this is not a weekend project, and it is not a beginner project. You will need to fabricate 10 custom PCBs from files that are not in this repository, source ferrofluid and the right carrier liquid, machine or 3D-print structural parts, and tune the magnetic fields until the droplets behave. There is no BOM, no assembly manual, and no guidance on calibration. The creators built this over two years as a university project, and the repository reflects that: it is a record of what they did, not a how-to guide for replication. If you have experience with motor control, custom PCBs, and iterative tuning, this is a genuinely rewarding challenge. If you are new to any of those, expect to spend months learning before the fluid moves the way you want it to.
IN THE REPO
NOT IN THE REPO
- —Firmware repository with code for the Teensy 4.1 controller and display logic.
- —CAD files present for the electromagnet module and mechanical structure.
- —No bill of materials — you will need to reverse-engineer the parts list from the CAD and PCB files.
- —Documentation is minimal: no assembly guide, no calibration procedure, no tuning notes for the ferrofluid.
- —10 custom PCBs are referenced but Gerbers are not in this repository.
- —GPL-3.0 licence — open for commercial use but derivatives must remain open.
- —The project took two students approximately two years to complete.
Can I build this?
Build at your own risk. Projects involve tools, electronics and sometimes mains voltage — follow the creator’s safety notes.
Partner · KickstarterHeyGears G1: 10M+ colors and transparent parts in one print, plus UV printing on flat objects. Figures, parts and labels — no painting.
Gallery
Start here
Navigation into the creator’s own docs — we don’t rewrite the guide, we route you to the source.
- 1.Read the firmware README and study the code structure (This is the only repository with documentation — start here to understand the control logic.)
- 2.Locate the PCB and CAD repositories(The Gerbers for the 10 custom PCBs are not in this repository — check the organisation page or contact the creators.)
- 3.Source ferrofluid and test the carrier liquid(The right ferrofluid concentration and carrier viscosity are critical — expect to experiment.)
- 4.Fabricate or order the PCBs(Once you have the Gerbers, budget for fabrication and component sourcing.)
Resources
Documentation, files and community threads for this build — we link straight to the original sources and never rehost the creator’s files.
Partner · KickstarterBluHub reads and burns Blu-ray/DVD/CD, adds USB-C, USB-A, SD/TF and 10 Gbps data — plug and play, grand-piano finish.
KNOWN ISSUES
- The bill of materials does not exist — you will spend days reverse-engineering the parts list from the CAD and PCB files before you can order anything.
- The 10 custom PCBs are mentioned but the Gerbers are not in this repository — you will need to hunt for them or contact the creators.
- Ferrofluid behaviour is highly sensitive to viscosity, temperature, and magnetic field strength — expect to spend weeks tuning before it looks like the demo video.
- 252 electromagnets running simultaneously need careful power supply design — underestimate this and you will trip breakers or burn traces.
- There is no calibration procedure documented — you will need to write your own tuning scripts or iterate blind.
- Ferrofluid stains are permanent and the fluid is messy during setup — plan your workspace accordingly.
Can I build a smaller version to test the concept first?
Yes, and you should — start with a 3×3 or 4×4 matrix to prove the coil design and ferrofluid behaviour before scaling to 252 pixels.
Where do I get the PCB files?
They are not in this repository. Check the Applied Procrastination GitHub organisation page or reach out to the creators directly.
What ferrofluid should I use?
The repository does not specify a brand or formulation — you will need to experiment with concentration and carrier liquid viscosity to match the behaviour in the demo.
How much power does this need?
That depends on how many coils you run simultaneously and at what current — the firmware controls timing, but you will need a supply that can handle peak load without sagging voltage.
Community builds
No community builds yet — be the first, we feature the best ones.
Discussion1
FROM THE COMPAREE TEAM
252 electromagnets, two years, and the biggest open-source ferrofluid display ever documented — what would you animate on yours first?
Applied Procrastination
Two students in Oslo built Fetch over approximately two years as a university project, pushing the scale of open-source ferrofluid displays far beyond prior work. The name reflects the iterative, experimental nature of the build.
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DISCLAIMER
- Comparee is not the author of the projects featured here. All rights to each project belong to its creator — every page links to the original source, and we never host creators’ files.
- Information is provided without warranty and may become outdated as projects evolve. Prices are indicative bands only — always check the creator’s parts list for current costs.
- Building and operating any project is at your own responsibility. Protective equipment, safe workshop practice and compliance with local regulations are the builder’s responsibility.
CompareeTEAM1mo agoedited
Practical notes from our verification: this repository contains the firmware and some CAD, but the 10 custom PCBs that drive the electromagnets are not included here — you will need to track those down separately before you can fabricate anything. There is no bill of materials, no assembly guide, and no tuning procedure for the ferrofluid, so plan for significant reverse-engineering work before the first droplet moves. The project is visually stunning and the ambition is clear, but replication will require advanced skills and patience. Ferrofluid stains permanently, so test your setup over surfaces you do not care about.