This disclosure provides a tire formed of a body having multiple plies and a tread that surrounds the body. In some implementations, the plies and/or the tread include a resonator that generates a resonant signal in response to being activated by locally generated power or by an externally generated excitation signal. Multiple resonators formed of carbon-containing materials are distributed in the plies and/or tread to respond to changes to the tire by altering a characteristic of the resonant signal. Such alterations include frequency shifting of the resonant signal and/or attenuation of the resonant signal. The resonator can be configured to resonate at a first frequency when a structural characteristic of a respective ply or tread is greater than a level, and to resonate at a second frequency different than the first frequency when the structural characteristic of the respective ply or tread is not greater than the level.