Open Source Linear Actuator from Carl Bugeja on Hackaday.io:

Inspired from my pcb motor project, this project is aimed to make a very thin low-torque linear pcb actuator.

The coils of this motors are made from 5/5mil coreless pcb windings. A 3d-printed rig with magnets is used to slide across the pcb and is actuated by the winding’s magnetic field.

All design files for this project are also open source\