An apparatus for effecting a vibrating motion comprises a resonant planar armature, a housing, an electromagnetic device attached to the housing for effecting an alternating electromagnetic field, a magnetic device coupled to the armature and to the electromagnetic field for alternatively moving the armature in a first and a second direction in response to the electromagnetic field. The resonant planar armature comprises a plurality of planar spring members arranged regularly about a central planar region within a planar perimeter region of the armature, and the spring members provide a restoring force normal to a movement of the central region of the armature caused by the alternating electromagnetic field.