US Patent 7581439 - Microsensors embedded in tires

http://www.freepatentsonline.com/7581439.html

This patent from Bridgestone teaches incorporating RFID microsensors in tires to detect overheating conditions. Claim 1 reads:

1. A pneumatic tire comprising:

a pair of bead rings;

a body cord ply extending between the bead rings;

an innerliner disposed inwardly of the body cord ply;

a belt layer disposed outwardly of the body cord ply;

a pair of sidewalls disposed outwardly of the body cord ply; and

a sensor layer including a plurality of micro-scale sized or smaller sensors each providing wireless signal data related to one or more physical properties of the tire, wherein the sensors activate to provide signals at a threshold temperature corresponding to an undesirable tire temperature or the sensors deactivate and cease providing signals at a threshold temperature corresponding to an undesirable tire temperature.