A novel methodology to fabricate freestanding (CNFs-PVA)-MSP sensors in wireless humidity sensing applications

A novel methodology to fabricate freestanding (CNFs-PVA)-MSP sensors in wireless humidity sensing applications has been developed. This innovative fabrication methodology integrates a spin-coating technique with a unique magnetic sandwich fixture technology. Based on the developed sensor's platform, the humidity sensing performance of the wireless sensors was studied at room temperature. The sensor's signal, represented by the resonant frequency (RF), exhibits a linear correlation with relative humidity (RH). Models have been uncovered to describe the sensing behavior of the humidity response. Additionally, the RF alteration demonstrates a linear dependence on the thickness of the CNFs-PVA composite layer. This study systematically explores and discusses the sensitivity, response time, and cyclic humidity sensing stability of the MSP-based sensors. Remarkably, the MSP-based sensors exhibit good stability in humidity sensing throughout a seven-day cyclic test. In summary, this novel fabrication methodology not only enables the fabrication of diverse wireless organic material-MSPbased sensors with appealing overall wireless humidity sensing performance but also provides a novel methodology for crafting miniaturized organic material-ferromagnetic material double-layer devices, offering advantages such as simple handling, cost-effectiveness, and high fabrication efficiency.