scholarly journals Acoustic Optical Fiber Sensor Based on Graphene Oxide Membrane

Sensors ◽  
2021 ◽  
Vol 21 (7) ◽  
pp. 2336
Author(s):  
Catarina S. Monteiro ◽  
Maria Raposo ◽  
Paulo A. Ribeiro ◽  
Susana O. Silva ◽  
Orlando Frazão
Keyword(s):  
Graphene Oxide ◽  
Signal To Noise Ratio ◽  
Optical Cavity ◽  
Optical Fiber Sensor ◽  
Signal Amplitude ◽  
Chemical Hazards ◽  
Fabry Perot ◽  
Fabrication Procedure ◽  
The Stability ◽  
Oxide Membrane

A Fabry–Pérot acoustic sensor based on a graphene oxide membrane was developed with the aim to achieve a faster and simpler fabrication procedure when compared to similar graphene-based acoustic sensors. In addition, the proposed sensor was fabricated using methods that reduce chemical hazards and environmental impacts. The developed sensor, with an optical cavity of around 246 µm, showed a constant reflected signal amplitude of 6.8 ± 0.1 dB for 100 nm wavelength range. The sensor attained a wideband operation range between 20 and 100 kHz, with a maximum signal-to-noise ratio (SNR) of 32.7 dB at 25 kHz. The stability and sensitivity to temperatures up to 90 °C was also studied. Moreover, the proposed sensor offers the possibility to be applied as a wideband microphone or to be applied in more complex systems for structural analysis or imaging.

scholarly journals Thermally Stimulated Desorption Optical Fiber-Based Interrogation System: An Analysis of Graphene Oxide Layers’ Stability

Photonics ◽  
2021 ◽  
Vol 8 (3) ◽  
pp. 70
Author(s):  
Maria Raposo ◽  
Carlota Xavier ◽  
Catarina Monteiro ◽  
Susana Silva ◽  
Orlando Frazão ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Optical Fiber ◽  
Optical Fiber Sensor ◽  
Layer By Layer ◽  
Film Stability ◽  
A Value ◽  
Device Reliability ◽  
Sensor Devices ◽  
Lbl Films ◽  
The Stability

Thin graphene oxide (GO) film layers are being widely used as sensing layers in different types of electrical and optical sensor devices. GO layers are particularly popular because of their tuned interface reflectivity. The stability of GO layers is fundamental for sensor device reliability, particularly in complex aqueous environments such as wastewater. In this work, the stability of GO layers in layer-by-layer (LbL) films of polyethyleneimine (PEI) and GO was investigated. The results led to the following conclusions: PEI/GO films grow linearly with the number of bilayers as long as the adsorption time is kept constant; the adsorption kinetics of a GO layer follow the behavior of the adsorption of polyelectrolytes; and the interaction associated with the growth of these films is of the ionic type since the desorption activation energy has a value of 119 ± 17 kJ/mol. Therefore, it is possible to conclude that PEI/GO films are suitable for application in optical fiber sensor devices; most importantly, an optical fiber-based interrogation setup can easily be adapted to investigate in situ desorption via a thermally stimulated process. In addition, it is possible to draw inferences about film stability in solution in a fast, reliable way when compared with the traditional ones.

Oscillation in the electrical conductivity of a thick graphene oxide membrane

2021 ◽  
Vol 129 (23) ◽  
pp. 235105
Author(s):  
L. Jamilpanah ◽  
M. Alihosseini ◽  
S. Ghasemi ◽  
N. Hassani ◽  
F. Peymanirad ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Graphene Oxide ◽  
Oxide Membrane

scholarly journals Liquid level sensor based on dynamic Fabry–Perot interferometers in processed capillary fiber

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Pablo Roldán-Varona ◽  
Rosa Ana Pérez-Herrera ◽  
Luis Rodríguez-Cobo ◽  
Luis Reyes-González ◽  
Manuel López-Amo ◽  
...  
Keyword(s):  
Optical Fiber Sensor ◽  
Liquid Level ◽  
Hollow Core ◽  
Immiscible Liquids ◽  
Fabry Perot ◽  
Detection Mode ◽  
Level Sensor ◽  
Core Fiber ◽  
Liquid Level Sensor ◽  
Silica Capillary

AbstractIn this work, a novel optical fiber sensor capable of measuring both the liquid level and its refractive index is designed, manufactured and demonstrated through simulations and experimentally. For this, a silica capillary hollow-core fiber is used. The fiber, with a sensing length of 1.55 mm, has been processed with a femtosecond laser, so that it incorporates four holes in its structure. In this way, the liquid enters the air core, and it is possible to perform the sensing through the Fabry–Perot cavities that the liquid generates. The detection mode is in reflection. With a resolution of 4 μm (liquid level), it is in the state of the art of this type of sensor. The system is designed so that in the future it will be capable of measuring the level of immiscible liquids, that is, liquids that form stratified layers. It can be useful to determine the presence of impurities in tanks.

Fabrication of Graphene Oxide Membrane with Multiple “Plug-ins” for Efficient Dye Nanofiltration

2021 ◽  
pp. 119504
Author(s):  
Jia Pang ◽  
Xiaolei Cui ◽  
Yang Feng ◽  
Zhenji Guo ◽  
Guodong Kong ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Oxide Membrane
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