Removable surface -wave networks for in-situ material health monitoring

A method of determining a surface characteristic of a surface under test, the method comprising:

• removably locating a surface wave network on the surface under test, wherein the surface wave network comprises:
• a dielectric substrate;
• a reactive grid comprising a plurality of metallic patches on a first surface of the dielectric substrate;
• a plurality of electronic nodes on the first surface of the dielectric substrate;
• and
• a ground plane on a second surface of the dielectric substrate opposite the first surface of the dielectric substrate, the ground plane permeable to radio frequency fields of the surface waves;
• operating a controller configured for causing a respective one of the electronic nodes to transmit at least one surface wave and configured for collecting data for signals received by at least one other of the plurality of electronic nodes;
• and
• processing the collected data to determine the surface characteristic of the surface under test.

An apparatus for measuring properties of a surface under test with surface waves comprising:

• a surface wave network comprising:
• a dielectric substrate;
• a reactive grid comprising a plurality of metallic patches on a first surface of the dielectric substrate;
• a plurality of electronic nodes on the first surface of the dielectric substrate;
• and
• a ground plane on a second surface of the dielectric substrate opposite the first surface of the dielectric substrate, the ground plane permeable to radio frequency fields of the surface waves.