Printed Wireless Battery-Free Sensor Tag for Health Monitoring of Polymer Composites

This article presents a fully printed wireless sensor tag for structural health monitoring of smart lightweight construction parts. The sensor concept aims for sustainability and was developed in line with the European Green Deal, fabricated by inkjet printing on uncoated paper substrate, working without the use of a battery or a chip. Measurement results show a wireless operation over a distance of 3 mm, a sensitivity of 4.16-kHz resonant frequency shift per % relative humidity for the humidity sensor, 165 kHz per 1% strain for the strain sensor, and a temperature coefficient of resistance of $1.61\times 10^{-3}\,\,\text{K}^{-1}$ for the temperature sensor. In case of all three sensors, the measurement data show a linear response and are in good agreement with literature and reference data.