An Embroidered Two-Dimensional Chipless Strain Sensor for Wireless Structural Deformation Monitoring

A wireless chipless sensor for structural deformation monitoring is proposed. The sensor is based on two resonant scatterers sewn on stretchable fabrics with conductive threads. The combination of the two scatterers allows for the detection of the strain in a 2-D plane. The backscattered response, as a function of frequency, is detected with the help of frequency-stepped continuous wave radar technique. The radar performs the detection by scanning the two orthogonal polarizations. It operates in the ISM band at 2.45 GHz. The proposed processing method achieves the 2-D extraction of the strain and the tensile force with the electromagnetic response of the sensor. Simulation and measurement results validate this new concept.