A conformal battery-free RF sensor for wireless and penetration acetone monitoring

초록

Wireless monitoring of volatile organic compounds (VOCs) in confined or difficult-to-access environments requires sensing platforms with conformal deployability and stable wireless readout. Here, we present a batteryfree radiofrequency (RF) sensor to deploy inside the chamber for room-temperature acetone detection, in which the dynamic response is wirelessly read out using an external antenna. As far as we know, this is the first time to introduce a penetrable battery-free wireless sensing platform for gas sensing, which meets the special requirements for inner non-metallic pipeline detection and highly enhances the deployment flexibility. In addition, the effects of conformal bending and dielectric interlayers were systematically evaluated to assess the sensor performance under practical deployment conditions. Built on a flexible polyimide substrate, the device adopts a separated LC architecture in which a ZnO-SnO2 composite fibrous sensing layer is integrated into the high-electric-field region. The gas-induced dielectric perturbations are transduced into resonance shifts, enabling quantitative acetone detection from 0 to 500 ppm with a sensitivity of -4.31 kHz/ppm and response/recovery time of 86/34 s. The sensor also maintains stable readout under bending deformation, humidity variation, and dielectric interlayers, demonstrating the strong geometric robustness and environmental adaptability. A sealedvessel evaporation test was further used as a simplified confined-space demonstration, highlighting the potential of RF resonators for passive wireless acetone sensing in confined or closed environments.

키워드