It’s a small linear ... The motor is basically a modified solenoid. There are sixteen neodymium magnets inside the shaft. The set of four coils is driven by an ATtiny44. Just like a stepper ...

If one-dimensional movement is enough for you, though, check out this linear stepper motor that works on a similar principle.

The L-239 is our highest load standard linear actuator. It can handle pushing forces of up to 66 lbs. The high-speed version reaches velocities of 2 inches/second. Choice of Servo and Stepper Motors.