A highly sensitive and miniaturized wearable antenna based on MXene films for strain sensing

With the prosperous development of wearable electronics, flexible radio-frequency wireless antenna sensors have attracted considerable interest due to their various applications in the Internet of things (IoT). However, vital issues including device configurations and materials restricted the miniaturization and flexibility of antenna sensors. In this work, we demonstrated a microstrip antenna wireless sensor consisting of a copper ground plane, a polydimethylsiloxane dielectric substrate and an MXene patch. Our optimized device possessed a small size (40 × 40 mm²) with a resonant frequency at 4.8 GHz and a frequency-shift range of 8% under different strains and matches well with 5G communications. Moreover, our antenna wireless sensor exhibited excellent mechanical flexibility and stable response to repetitive stimulations. The strain sensitivity of 20 is also impressive among similar antenna sensors. The demonstrations on human body and cantilever motion monitoring were conducted with desirable stability and sensitivity, where the sensor showed obvious shifted resonant frequencies while the reflection coefficient was maintained at around −25 dB, revealing its great potential in healthcare monitoring, construction diagnosis and IoT.