Blunt Impact Indicator Methods

A blunt impact indicator device, comprising:

• a substrate;
• a breakable electrical conductor disposed on or embedded in said substrate and having first and second terminals;
• a voltage supply connected to said first and second terminals of said breakable electrical conductor;
• and
• a continuity indicator electrically connected to said breakable electrical conductor.

A method for monitoring a structure for damage due to blunt impact, comprising:

• placing a radio-frequency identification circuit and first and second serpentine electrical conductors on a substrate, the first and second serpentine electrical conductors having respective first terminals electrically connected to respective terminals of the radio-frequency identification circuit and respective second terminals which are not electrically connected to each other;
• placing a multiplicity of rupturable shells over the first and second serpentine electrical conductors, each shell having an internal volume at least partially filled with electrically conductive fluid;
• and
• interrogating the radio-frequency identification circuit by transmitting a radio-frequency signal through a volume of space intersected by radio-frequency identification circuit,
• wherein any response to the interrogation by the radio-frequency identification circuit will have a frequency which is a function of an impedance of an antenna formed if the first and second serpentine electrical conductors are electrically coupled to each other by electrically conductive fluid escaped from the multiplicity of shells.

A blunt impact indicator device, comprising:

• a substrate having a surface;
• a first multiplicity of rupturable shells disposed in proximity to said surface of said substrate, each shell of said first multiplicity having an internal volume;
• a first fluid having a first pH level disposed in the internal volumes of respective shells of said first multiplicity of shells;
• and
• a layer of pH-sensitive material disposed adjacent to said first multiplicity of rupturable shells.