Sensor Systems for Process and condition Monitoring

Implementation of zero-power sensors with sensory metamaterials for applications in lightweight structural engineering

© Fraunhofer ENAS
Implementation of a sensor metamaterial by an array of electromagnetic resonators with subwavelength dimensions.

Due to their structure, metamaterials show a strong frequency filter behavior, which changes with material changes. This circumstance is used to implement a passive sensor function, so that passive structure and condition monitoring of lightweight structures becomes possible.
For this purpose, metamaterials and their application as zero-power sensors for use in lightweight structures were being investigated within the framework of the Federal Excellence Cluster MERGE »Technologies for Multifunctional Lightweight Structures« of Chemnitz University of Technology in close cooperation with the Fraunhofer ENAS.
The approach pursued here to realize a passive and material-immanent sensor function for lightweight structures uses regularly arranged electromagnetic resonators with sub-wavelength dimensions and their integration into lightweight structures. Due to the strong frequency filter behavior of the resonator arrays, a specific frequency response can be generated. Changes in material or structure influence the frequency filter behavior, which is reflected in the displacement of significant resonance points.
By means of electromagnetic waves in connection with a transmission or reflection measurement, the changes in the frequency behavior can be determined and conclusions can be drawn about the presence of a structural or material change.

The work was carried out within the framework of the Federal Excellence Cluster EXC 1075 »MERGE – Technologies for Multifunctional Lightweight Structures« and funded by the German Research Foundation (DFG). The financial support was gratefully acknowledged.