| 摘要 |
<p>A device adapted to provide an indication of a condition of a structure (202) includes a circuit (L, R, C, C 0 ) configured to be electrically resonant at a predetermined frequency in a normal state. The circuit at least partially comprises components formed using Direct Write. In use, the circuit is connected to or formed on a part of the structure such that a change in a property of the part of the structure causes the circuit to be electrically resonant at a frequency different to the predetermined frequency, thereby providing an indication of a condition of the structure.</p> |
