An actuator (100) includes an inner element (120) coupled to an outer element (110) by a linear-motion bearing (115) that provides a single degree of translational movement of the inner element with respect to the outer element along a longitudinal axis (10). The inner element includes a permanent magnet (122) and the outer element includes a conductive winding (111) with a first coil (112a) wound in first direction around a first pole (124a) of the permanent magnet and a second coil (112b) wound in a second direction around a second pole (124b) of the permanent magnet. The actuator may be used in an intraoral scanner.
