NFC for Powering Sensors in Concrete

Within this paper a concept for a NFC compatible wireless power transfer system is presented that is able to supply sensors embedded over 10 cm deep into concrete. The goal is on the one hand the use of only commercially easily available components and on the other hand the integration of an energy storage system to enable a self-sufficient function without active energy transfer. Therefore, we discuss the basic requirements to achieve magnetic coupling of reader and transponder and present a system concept for a wireless power transfer system that is tested in measurements with two different embedding depths. Depending on the thickness and water content of concrete, power transmission ranging up to almost one Watt has been achieved in a proof of concept implementation.