Design, fabrication and characterization of capacitive humidity sensors based on emerging flexible technologies

Piezoelectric polymer nano compositesfor humidity sensors applications are manufactured in this work by adding nano Yttrium oxides (Y2O3) in three ratios (3,6and 9 wt.%) to the polymeric blend consist of (1:9) poly vinyl difluoride (PVDF) and poly methyl methacrylate (PMMA). FTIR results showed that PVDF addition to PMMA causes shifting in the blue direction and there is no chemical bonding between the prepared composites components,butthere is a significant increase in the rate of permeabilityat higherY2O3 ratio. This addition causes the hardness to be increased linearly. Morphology results showed, that the lower ratios of Y2O3 causes the surface became smoother and homogeneous, while higher ratios increase the roughness of the surface. These compositesgive piezoelectric behavior where the electrical resistance decreases by increasing the pressure. With regard to the dielectric properties the losses coefficient increase by increasing the frequency while dielectric constant decreases. The composites showed to be more hydrophilic by increasing theY2O3 ratio,which suggests these composites for water storage applications. The results show possibility of using these composites as humidity sensorsin relative humidity less than 70%, where the electrical resistivity decreases as the relative humidity increasing.

Download Full-text

Fabrication and characterization of humidity sensors based on CVD grown MoS2 thin film

2017 IEEE 17th International Conference on Nanotechnology (IEEE-NANO) ◽

10.1109/nano.2017.8117408 ◽

2017 ◽

Cited By ~ 2

Author(s):

Shiqi Guo ◽

Abbas Arab ◽

Sergiy Krylyuk ◽

Albert V. Davydov ◽

Mona E. Zaghloul

Keyword(s):

Thin Film ◽

Humidity Sensors ◽

Fabrication And Characterization

Download Full-text

Fabrication and Characterization of Flexible and Miniaturized Humidity Sensors Using Screen-Printed TiO2 Nanoparticles as Sensitive Layer

Sensors ◽

10.3390/s17081854 ◽

2017 ◽

Vol 17 (8) ◽

pp. 1854 ◽

Cited By ~ 18

Author(s):

Georges Dubourg ◽

Apostolos Segkos ◽

Jaroslav Katona ◽

Marko Radović ◽

Slavica Savić ◽

...

Keyword(s):

Tio2 Nanoparticles ◽

Sensitive Layer ◽

Humidity Sensors ◽

Fabrication And Characterization ◽

Screen Printed

Download Full-text

Fabrication and Characterization of Flexible Capacitive Humidity Sensors Based on Graphene Oxide on Porous PTFE Substrates

Sensors ◽

10.3390/s21155118 ◽

2021 ◽

Vol 21 (15) ◽

pp. 5118

Author(s):

Zhenyu Wei ◽

Jianqiu Huang ◽

Wenhao Chen ◽

Qingan Huang

Keyword(s):

Graphene Oxide ◽

Dynamic Properties ◽

High Sensitivity ◽

Fast Response ◽

Humidity Sensors ◽

Flexible Sensors ◽

Response Recovery ◽

Sensing Material ◽

Fabrication And Characterization

Porous polytetrafluoroethylene (PTFE) is physically flexible, thermally and chemically stable, relatively inexpensive, and commercially available. It is attractive for various flexible sensors. This paper has studied flexible capacitive humidity sensors fabricated on porous PTFE substrates. Graphene oxide (GO) was used as a sensing material, both hydrophobic and hydrophilic porous PTFE as the substrates, and interdigitated electrodes on the PTFE substrates were screen-printed. SEM and Raman spectrum were utilized to characterize GO and PTFE. An ethanol soak process is developed to increase the yield of the humidity sensors based on hydrophobic porous PTFE substrates. Static and dynamic properties of these sensors are tested and analyzed. It demonstrates that the flexible capacitive humidity sensors fabricated on the ethanol-treated hydrophobic PTFE exhibit high sensitivity, small hysteresis, and fast response/recovery time.

Download Full-text