"SENSOR: Embedded sensors gauge materials' inner states"
Sensors developed by Elizabethtown College researchers could pave the way for next-generation materials that would be equipped with 50-ohm coaxial connections that engineers could "ping" to read out the material's internal state. The embedded capacitive sensors could be the cure for advanced processing of materials from carbon nanotube-reinforced composites to plain old concrete, enabling functions ranging from elaborate process control monitoring to simple electronic pop-up alerts that would go the traditional turkey timer one better. "The sensors we make are very small capacitors � I'm talking picofarad parallel-plate capacitors with the material serving as the dielectric. At those frequencies, you don't need much loading to get an effective match to a 50-ohm line," said Nathaniel Hager III, an adjunct professor in the physics and engineering department at Elizabethtown (Pa.) College. Hager performed the work with materials chemist Roman Domszy. A patent was awarded just days ago covering sensing and instrumentation using time-domain reflectometry (TDR) dielectric spectroscopy.