High Sensitivity Humidity Detection Based on Functional GO/MWCNTs Hybrid Nano-Materials Coated Titled Fiber Bragg Grating

Abstract

A high performance humidity sensor using tilted fiber Bragg grating (TFBG) and functional graphene oxide (GO)/multi-walled carbon nanotubes (MWCNTs) hybrid nano-materials was proposed. The humidity-sensitive material with three-dimensional (3D) structure was synthesized by the MWCNTs and GOs. Comparing with traditional two dimensional (2D) GOs film, water molecules could be absorbed effectively due to the larger ripples and more holes in GO/MWCNTs layers. The water molecule will fill the entire space in the 3D structure instead of air, which further enhances the absorption efficiency of the hybrid nanomaterial. TFBG as a compact and robust surrounding complex dielectric constant sensing platform was utilized. The mode coupling coefficient or the amplitude of TFBG cladding mode will vary sharply with the imaginary part of permittivity of the hybrid nanomaterial, realizing the high performance RH sensing. In the experiments, we successfully demonstrated that this 3D structural nanomaterial composed by the MWCNTs and GOs has significant advantages for expanding the range of humidity detection (range from 30% to 90%) and enhancing the detection sensitivity (0.377 dB/% RH is twice more than humidity sensor with 2D GO film). The TFBG-based RH sensor also exhibits good repeatability and stability. Our proposed humidity sensor has potential application in environmental and healthy monitoring fields.

Towards a fast and stable tachypnea monitor: a C60-Lys enabled optical fiber sensor for humidity tracking in breath progress

“…However, these materials exhibit low-refractive-index changes after adsorbing water molecules and require thick films to achieve a sufficient optical signal response. Consequently, most of these sensors have response times longer than 10 s. Moreover, graphene oxide (GO), as a derivative of 2D material graphene, is drawing extensive research in high-performance fiber RH sensors owing to the small size effect, high surface-area-to-volume ratio, and abundant hydrophilic groups [20][21][22] . The best performances of a GO enabled fiber humidity sensor were 45 ms and 115 ms in response and recovery progress, respectively [11] .…”

A free-standing humidity sensor with high sensing reliability for environmental and wearable detection

“…Humidity detection and management play a vital role in creating a pleasant, safe, green, and energy-efficient environment. Measuring humidity within the environment has been a dramatic proliferation of research in the applications spanning from the governance of the atmosphere and soil to the management of industrial manufacture, agricultural production and physiological health [1][2][3]. Besides, moisture constantly evaporates from the mouth and the skin surface because of the sensible and insensible perspirations.…”

Fabrication and Sensing Application of Phase Shifted Bragg Grating Sensors

“…With the progress of FBG inscribe technology, many innovative forms of Bragg gratings have been realized, such as chirped FBG [ 16 , 17 , 18 , 19 , 20 ], titled FBG [ 21 , 22 , 23 , 24 ] and phase-shifted fiber Bragg grating (PS-FBG) [ 25 , 26 , 27 , 28 ]. Among them, PS-FBG has attracted extensive attention [ 29 ].…”