Activatable rf tags with variable read range

An RF tag, comprising:

• an integrated circuit;
• an antenna, having a first antenna portion and a second antenna portion;
• wherein the first antenna portion is electrically connected in a closed circuit with the integrated circuit, and
• an activatable environmental exposure indicator having a conductive state and a nonconductive state,
• wherein the second antenna portion is in the closed circuit with the integrated circuit when the activatable environmental exposure indicator is in the conductive state and second antenna portion is in an open circuit when the activatable environmental exposure indicator is in the nonconductive state,
• wherein the activatable environmental exposure indicator includes a plurality of microcapsules, each microcapsule having a nonconductive frangible shell containing a payload including a conductive material and a liquefiable material,
• wherein the liquefiable material is configured to liquefy responsive to a predetermined environmental exposure,
• wherein each frangible shell is configured to continue to contain a respective payload when the liquefiable material is liquefied, and
• wherein each frangible shell is configured to rupture in response to an application of an activation action exceeding a predetermined activation threshold, releasing the respective payload,
• wherein, after the frangible shells are ruptured responsive to the activation action, and responsive to the liquefiable material being liquified, the activatable environmental exposure indicator transitions to the conductive state, thus establishing the closed circuit between the second antenna portion and the integrated circuit.