Suspended graphene sensor with controllable width and electrical tunability via direct-write functional fibers

Regmi, Abiral; Shin, Dongwoon; Kim, Jong-Hyun; Choi, Shi‐Hoon; Chang, Jiyoung

doi:10.1016/j.jmapro.2020.08.040

Cited by 7 publications

(8 citation statements)

References 43 publications

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“…Graphene Synthesis and Transfer: Graphene was synthesized on Cu foils as in our previous work [79] and transferred to the sensor device using standard procedures as in the published literature. [41] Briefly, graphene is thermally grown on Cu foils using a chemical vapor deposition process at 1040 °C with methane as a precursor gas.…”

Section: Methodsmentioning

confidence: 99%

“…Graphene film on Cu is then spin-coated with PMMA, and the Cu foil is etched with a 2% APS solution. The resulting Gr-PMMA film is transferred to the target device employing the scooping technique and is allowed to dry at room temperature for about 12 h. Finally, the PMMA layer is dissolved in acetone via a vertical submersion process, [79] preserving high-quality suspended mono and bilayer graphene. Fabrication of PEDOT: PSS-PEO Nanofiber: 0.014 gm of PEO (4 000 000 gm mol −1 ) is first dissolved in 0.25 gm of ultrapure deionized water (DI) water at 45 °C using a magnetic stirrer for 3 h. The use of such high molecular weight PEO improves the spinnability of the final solution.…”

Section: Methodsmentioning

confidence: 99%

“…Graphene film on Cu is then spin‐coated with PMMA, and the Cu foil is etched with a 2% APS solution. The resulting Gr‐PMMA film is transferred to the target device employing the scooping technique and is allowed to dry at room temperature for about 12 h. Finally, the PMMA layer is dissolved in acetone via a vertical submersion process, [ 79 ] preserving high‐quality suspended mono and bilayer graphene.…”

Section: Methodsmentioning

confidence: 99%

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Suspended Graphene/PEDOT: PSS‐PEO Channel for H₂ Gas Sensing Fabricated Using Direct‐Write Functional Fibers

Regmi

Shin

et al. 2023

Adv Materials Technologies

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and calibrate the sensors before detecting target gases. Second, a gas sensor's performance also depends on the system optimization, such as signal chain design, power consumption, etc., and sensor's operating conditions, such as temperature, humidity, pressure, test chamber design, etc. Finally, all sensors age, drift in performance, and ultimately fail at the end of their life. The cost of operation can be significantly decreased by effectively predicting the sensor's life and reducing unnecessary sensor replacements. In this research work, we fabricate a simple, low-cost, low-power consuming, and robust gas sensor that can detect Hydrogen (H 2 ) gas at a very low concentrations with enhanced sensitivity.Hydrogen (H 2 ) gas is a promising clean and green energy source. H 2 gas, with properties such as high energy density, renewability, and eco-friendly nature, is rising as a potential candidate to replace conventional fossil fuels in the automotive and industrial applications field. [1][2][3] Nevertheless, the low combustion energy (0.02 meJ) and wide flammable range (4-75%) of H 2 gas raise safety concerns and warrant an easy, quick, and reliable leakage detection method. [4,5] Typical commercial H 2 gas sensors employ metal oxide materials, such as SnO 2 , ZnO, and TiO 2 , due to their higher sensitivity toward detecting H 2 . [6][7][8] However, these sensors suffer from high operating temperatures (typically 200-500 °C) and usually have low selectivity. Other than conventional materials, conductive polymers have been studied as alternative sensing materials in chemical sensing to leverage simple processing, chemical versatility, and wide availability. [9] Poly(3,4-ethylene dioxythiophene) doped with polystyrene sulfonate (PEDOT: PSS) is the most commonly used conductive polymer which has attracted significant interest due to its high electrical conductivity, high stability, and ease in the processing. [10] The electrical property of PEDOT: PSS can be tailored via redox reactions and charge transfer due to doping. [11][12][13][14] PEDOT: PSS doped with nanocarbon materials is expected to achieve enhanced sensing properties owing to their high surface-to-volume ratio. Graphene (Gr), among various nanocarbon materials, is the most widely used because of its exceptional physical, chemical, mechanical, and electrical properties. [15][16][17][18] Although pristine graphene has proved low sensitivity toward detecting H 2 molecules, [15,19] chemically modified graphene/PEDOT: PSS nanocomposite films have demonstrated enhanced sensing response with a much shorter response and recovery time. [20] When suspended as a nanoscale bridge, In this study, the hydrogen gas (H 2 ) sensing mechanism of suspended graphene (Gr)/ Poly(3,4-ethylene dioxythiophene): Poly(styrene sulfonate) -Polyethylene oxide (PEDOT: PSS-PEO) composite nanoscale channels precisely patterned with near-field electrospinning is investigated. Suspended Gr/PEDOT: PSS-PEO nanoscale channels not only have a higher surface-to-volume ratio for easy diffusion...

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Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

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Suspended Graphene/PEDOT: PSS‐PEO Channel for H₂ Gas Sensing Fabricated Using Direct‐Write Functional Fibers

Regmi

Shin

et al. 2023

Adv Materials Technologies

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“…Details of graphene synthesis and microscale channeling can be found in previous works, which provide originality and in-depth information [ 43 , 44 ]. In Figure 3 a, the single-layer graphene was synthesized by the chemical vapor deposition (CVD) process [ 43 , 44 ]. A copper film was used for the growth substrate.…”

Section: Methodsmentioning

confidence: 99%

“…Since an ultrahigh molecular weight of PEO is used as a rich crystalline polymer solution for the NFES, the deposited fiber (width of 80–100 µm) served as a barricade mask that endures the oxygen plasma while etching the graphene. As a result, only the protected region covered by the spun fiber remained as a graphene photosensor channel [ 43 , 47 ], whereas the uncovered graphene was fully eliminated [ 48 ].…”

Section: Methodsmentioning

confidence: 99%

Printing Polymeric Convex Lenses to Boost the Sensitivity of a Graphene-Based UV Sensor

2022

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Ultraviolet (UV) is widely used in daily life as well as in industrial manufacturing. In this study, a single-step postprocess to improve the sensitivity of a graphene-based UV sensor is studied. We leverage the advantage of electric-field-assisted on-demand printing, which is simply applicable for mounting functional polymers onto various structures. Here, the facile printing process creates optical plano-convex geometry by accelerating and colliding a highly viscous droplet on a micropatterned graphene channel. The printed transparent lens refracts UV rays. The concentrated UV photon energy from a wide field of view enhances the photodesorption of electron-hole pairs between the lens and the graphene sensor channel, which is coupled with a large change in resistance. As a result, the one-step post-treatment has about a 4× higher sensitivity compared to bare sensors without the lenses. We verify the applicability of printing and the boosting mechanism by variation of lens dimensions, a series of UV exposure tests, and optical simulation. Moreover, the method contributes to UV sensing in acute angle or low irradiation. In addition, the catalytic lens provides about a 9× higher recovery rate, where water molecules inside the PEI lens deliver fast reassembly of the electron-hole pairs. The presented method with an ultimately simple fabrication step is expected to be applied to academic research and prototyping, including optoelectronic sensors, energy devices, and advanced manufacturing processes.

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Electrospun aligned nanofibers: A review

Han

Wang

Yuan

et al. 2022

Arabian Journal of Chemistry

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Suspended graphene sensor with controllable width and electrical tunability via direct-write functional fibers

Cited by 7 publications

References 43 publications

Suspended Graphene/PEDOT: PSS‐PEO Channel for H₂ Gas Sensing Fabricated Using Direct‐Write Functional Fibers

Suspended Graphene/PEDOT: PSS‐PEO Channel for H₂ Gas Sensing Fabricated Using Direct‐Write Functional Fibers

Printing Polymeric Convex Lenses to Boost the Sensitivity of a Graphene-Based UV Sensor

Electrospun aligned nanofibers: A review

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Suspended graphene sensor with controllable width and electrical tunability via direct-write functional fibers

Cited by 7 publications

References 43 publications

Suspended Graphene/PEDOT: PSS‐PEO Channel for H2 Gas Sensing Fabricated Using Direct‐Write Functional Fibers

Suspended Graphene/PEDOT: PSS‐PEO Channel for H2 Gas Sensing Fabricated Using Direct‐Write Functional Fibers

Printing Polymeric Convex Lenses to Boost the Sensitivity of a Graphene-Based UV Sensor

Electrospun aligned nanofibers: A review

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Product

Resources

About

Suspended Graphene/PEDOT: PSS‐PEO Channel for H₂ Gas Sensing Fabricated Using Direct‐Write Functional Fibers

Suspended Graphene/PEDOT: PSS‐PEO Channel for H₂ Gas Sensing Fabricated Using Direct‐Write Functional Fibers