Rhombus-patterned flexible self-supported PVDF-based humidity sensor for respiratory monitoring

Humidity sensors are crucial in sectors such as environmental sustainability, industrial production, and healthcare. The fabrication of sandwich-type humidity sensors that can serve as substrates, sensing materials, and electrodes remains a focus of effort in the healthcare sector now. This research entails the synthesis of rhombus-patterned flexible nanofiber membranes (PPZN) utilizing polyvinylidene fluoride (PVDF) and zinc oxide nanoparticles (ZnO NPs) as the foundational substrates, while employing polyvinylpyrrolidone (PVP) as a structural modulator and hydrophilic modifier. The fabrication process involved the utilization of electrospinning technique for membrane production. Furthermore, polyaniline (PANI) is in-situ polymerized onto rhombus-patterned nanofiber membrane to form a core-sheath structure (PPZN), which serves as an electrode to produce a rhombus-patterned flexible self-supported PVDF-based humidity sensor (YPPZN). The combination of hydrophilic and hydrophobic properties facilitates the transfer of water molecules. At the same time, the unique diamond structure and high surface area provide favorable channels for the transportation of water molecules. YPPZN offers a broad range of relative humidity for operation (13%–93% RH), excellent sensitivity, and quick response and recovery times (20s/75s). The YPPZN humidity sensor likewise provides excellent flexibility and dependability, which can be configured into an arch inside a mask for ongoing real-time monitoring of human respiratory parameters. [Display omitted] •A flexible humidity sensor was developed by employing PVP as a structure regulator and hydrophilic modifier for PVDF.•Tthe rhombus pattern and high surface area of the nanofibers provide favorable pathways for water molecule diffusion.•By utilizing PANI as the humidity-sensitive and electrode material, ensuring the flexibility of the sensor.•The sensor demonstrates outstanding flexibility and self-supporting capabilities.