How do you go about making a mirror with 128 segments, each of which can be independently angled? That was the question that a certain bloke over at [Time Sink Studio] found himself pondering on, to ultimately settle on a whole batch of mini-actuators bought through AliExpress. These stepper-based actuators appear to be akin to those used with certain Oppo smartphones with pop-up camera, costing less than half a dollar for a very compact and quite fast actuator.
The basic design is very much akin to a macro version of a micromirror device, as used in e.g. DLP projectors, which rely on a kinetic mirror mount to enable precise alignment. With the small actuators travelling up to 8 mm each, the mirrors can cover 73 mm at a distance of 4 meters from a wall.
With the required angle of the mirror being effectively just the application of the Pythagorean theorem, the biggest challenge was probably calibrating these linear motors. Since they’re open loop devices, they are zeroed much like the steppers on 3D printers, by finding the end limit and counting steps from that known point. This doesn’t make drift impossible, but for projecting light onto walls it’s clearly more than good enough.
Very clever use of the actuators.
Danny Rozin has been making “living mirrors” for about 20 years but his most well known have mostly been pivoting along a single axis to make non-mirrored materials seem “mirror-esque”.
This is a totally different take and I think quite creative.
https://www.smoothware.com/danny/
In a coordinate system spanned by the disciplines of
– repeating something often
– doing something for a long time, and
– making many units,
most projects remain cowardly around the origin. As with fastener counting (cue https://hackaday.com/2025/07/06/fastener-fusion-automating-the-art-of-counting/ ), I enjoy this project for venturing out a bit into deep project space.
There are different learning opportunities, including have one’s elegant solution beaten by boring approaches (like using a camera to re-calibrate the mirrors on the fly instead of adding encoders and closed-loop control).
It seems [Time Sink Studio] will continue to work on this project and I’m looking forward to him addressing the weather-proofing challenge and temperature excursions resulting from it.
Other light tricks
https://phys.org/news/2026-01-quantum-alchemy-feasible-excitons.html
https://techxplore.com/news/2026-01-solid-state-material-hydrogen-sunlight.html
Nice to see a youtube on HaD where the author actually links to various parts used.
I much prefer actual hardware-hackers instead of a clicks-collectors like so many videos seem to be.
agreed, great video.