In this study, we propose a tilted fiber Bragg grating (TFBG) humidity sensor fabricated using the phase mask method to produce a TFBG that was then etched with five different diameters of 20, 35, 50, 55 and 60 μm, after which piezoelectric inkjet technology was used to coat the grating with graphene oxide. According to the experimental results, the diameter of 20 μm yielded the best sensitivit...

We developed a highly sensitive humidity sensor based on the combination of ultrahigh-frequency film bulk acoustic resonator (FBAR) and nano-assembled polyelectrolyte (PET) thin films. The water molecule absorption efficiency was optimized by forming loosely-packed PET nanostructures. Then, the humidity sensing characteristics were analyzed in terms of sensitivity, linearity, reversibility, sta...

The present study highlights the interdependence of ambient humidity levels on the electrical parameters of organic-inorganic hybrid composite based humidity sensor at varied AC frequencies of input signal. Starting from the bottom, the layer stack of the fabricated humidity sensor was 200-nm silver (Ag) thin film and 4 μm spun-coated PEPC+NiPC+Cu2O active layer. Silver thin films were deposite...

This article describes the effect of the lateral size of graphene oxide (GO) on the humidity sensing properties of a GO-based sensor. The GO size effect on the humidity sensing performance was evaluated on gold electrodes drop-coated with either an ultralarge graphene oxide (UGO) sheet (lateral size = 47.4 ± 22.2 μm) or a small-sized graphene oxide (SGO) sheet (lateral size = 0.8 ± 0.5 μm). The...

Wireless sensor networks are used in different fields. One of the fields, where such sensors can be used is apiculture for honey bee (Apis Mellifera L.) monitoring (for example, temperature and humidity data acquisition). This paper introduces a wireless sensor network system for bee colonies online monitoring. The developed wireless system consists of several wireless measurement nodes which t...

Thin films of Nickel phthalocynine (NiPc) of different thicknesses (100, 150 and 200 nm) were deposited by thermal evaporator on glass substrates with preliminary deposited aluminum electrodes to form Al/NiPc/Al surface-type capacitive humidity sensors. The capacitance-humidity relationships of the sensors were investigated at humidity levels from 35 to 90% RH. It was observed that the capacita...

A capacitive coupling structure is developed to improve the performances of a capacitive complementary metal oxide semiconductor (CMOS) microelectromechanical system (MEMS) humidity sensor. The humidity sensor was fabricated by a post-CMOS process. Silver nanowires were dispersed onto the top of a conventional interdigitated capacitive structure to form a coupling electrode. Unlike a convention...

Along with magnetic properties, the spinel ferrites exhibit promising electrical properties, deployment of which results into evolution of new area of applications as the electronic sensor materials. The electrical properties significantly depend upon the environmental compositions, for which it has been exposed. The electrical resistance of these sensor materials varies not only with gas conce...

The optical characteristics of graphene oxide (GO) were explored to design and fabricate a GO-based optical humidity sensor. GO film was coated onto a SU8 polymer channel waveguide using the drop-casting technique. The proposed sensor shows a high TE-mode absorption at 1550 nm. Due to the dependence of the dielectric properties of the GO film on water content, this high TE-mode absorption decre...