When it is powered up, the twin-eye assembly sits on a black stand and moves its two gray printed eyeballs, replicating eye motion in a very small footprint. The stated aim was to build the world's smallest animatronic eye, and the finished mechanism does run.
The construction approach is the part that stands out for me. Instead of a bulky conventional mechanism, the eye cups are spherical and are moved by electromagnetic actuation. The coils are enameled copper wire wrapped around metal cores, and the chassis parts are 3D printed. Miniature ball bearings, copper magnet wire and screw terminal blocks round out the hardware, and the assembly also includes fine lead wires along with yellow Kapton tape. At that scale, tweezers were needed just to adjust a miniature joint.
Before committing to any of it, the maker searched online for existing 3D printed animatronic eye designs, with an iPad displaying the image searches. The decision after that was to disregard traditional animatronic eye designs entirely and go the electromagnetic route. Given the sub-miniature target, that seems like a smart call to me; conventional linkages would eat space fast, and the direct drive keeps the moving parts minimal.
One thing worth flagging: the maker stated there was no prior animatronics experience before this project. Pulling off a working dual-eye mechanism at this size on a first attempt is impressive, and it leaves me curious what a second revision would look like.
Project by Breaking Taps. Watch it on their YouTube channel: