Self-detaching anti-theft device for retail environment

A security tag, comprising:

• a single enclosure having a first portion spaced apart from a second portion by a gap;
• a pinion gear pivotally disposed within the first portion of the single enclosure;
• a rack gear disposed within the first portion of the single enclosure which converts rotational motion of the pinion gear in a first direction into linear motion in a second direction;
• a pin coupled to the rack gear and mechanically transitioned from an unengaged state to an engaged state via linear movement of the rack gear,
• the unengaged state is a state in which the pin is retracted into the first portion of the single enclosure, and
• the engaged state is a state in which (a) an elongate body of the pin passes through the gap and (b) an end of the pin resides within an aperture formed in the second portion of the single enclosure, the first and second portions of the single enclosure having static positions relative to each other at all times of the security tag's use;
• a pawl configured to mechanically retain the pin in the engaged position by preventing movement of the pinion gear in a third direction opposed to the first direction;
• an electronic circuit disposed with the single enclosure operative to cause an automatic release of the pawl in response to a reception of a wireless signal thereat;
• and
• a resilient member resiliently biasing the pin toward the first portion of the single enclosure so that the pin transitions from the engaged state to the unengaged state when the pawl is released without any human assistance or mechanical assistance by a device external to the security tag.