Sharif Digital Repository

Highly sensitive flexible humidity sensors based on graphene quantum dots (GQDs) were developed. The GQDs were prepared using a facile hydrothermal method and characterized considering morphological, structural, and compositional experiments. Then, their humidity sensing properties in correlation with flexibility characteristics were investigated. Good selectivity and response (∼390 for a RH change of 99%), broad detection range (1-100% RH), rather short response and recovery times (12 and 43 s, respectively) as well as flexibility were obtained, demonstrating that the GQD sensors have potential for application in wearable electronics and RH monitoring. Detection of hydrogen (H2) gas by the... 

The deposition of tetrakis (4-sulonatophenyl) porphyrin (TPPS) thin film on optical fibers presents many possibilities for sensing applications. The J-form aggregation with a narrow and sharp spectral feature at about 490 nm and its sensitivity to humidity have been discussed; a fast change of wavelength occurs according with variation in the humidity level. The reproducibility and high sensitivity of TPPS-coated fibers, along with the capabilities of optical fibers, suggest the device as a good candidate for humidity sensing in harsh environments. © 2018, The Author(s)  

With the advent of the Internet of Things (IoT), the development of self-powered sensors has received much attention. Introducing triboelectric nanogenerators (TENGs) as a power source that converts mechanical movement into electrical signals has been admired recently. Moreover, the monitoring of humidity has become enormously essential in several technological contexts from environment monitoring to biomedical applications, thus joining these two subjects provides a huge benefit in achieving self-powered humidity sensors. Here, in this research, facile, low-priced and self-powered humidity sensors are fabricated utilizing transition-metal dichalcogenides (TMD) nanosheets. Semi-vertical SnS2...