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Flow-induced voltage generation over monolayer graphene in the presence of herringbone grooves.

Lee SH, Kang YB, Jung W, Jung Y, Kim S, Noh HM - Nanoscale Res Lett (2013)

Bottom Line: Phys.We found that the flow-induced voltage decreased significantly in the presence of herringbone grooves in both parallel and perpendicular alignments.These results support our previous interpretation.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology, Daejeon 305-701, Republic of Korea. soohyun@kaist.ac.kr.

ABSTRACT
While flow-induced voltage over a graphene layer has been reported, its origin remains unclear. In our previous study, we suggested different mechanisms for different experimental configurations: phonon dragging effect for the parallel alignment and an enhanced out-of-plane phonon mode for the perpendicular alignment (Appl. Phys. Lett. 102:063116, 2011). In order to further examine the origin of flow-induced voltage, we introduced a transverse flow component by integrating staggered herringbone grooves in the microchannel. We found that the flow-induced voltage decreased significantly in the presence of herringbone grooves in both parallel and perpendicular alignments. These results support our previous interpretation.

No MeSH data available.


Device preparation. (a, b) Schematic illustration of the test device without and with herringbone grooves. (c) Raman spectra of monolayered graphene. (d) Fabrication and assembly. (e) SEM images of herringbone grooves. (f) Four different types of device configurations according to the electrode-flow alignment and the presence of herringbone grooves.
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Figure 1: Device preparation. (a, b) Schematic illustration of the test device without and with herringbone grooves. (c) Raman spectra of monolayered graphene. (d) Fabrication and assembly. (e) SEM images of herringbone grooves. (f) Four different types of device configurations according to the electrode-flow alignment and the presence of herringbone grooves.

Mentions: Here, we modified the flow to have a transverse component by introducing staggered herringbone grooves in the microchannel to further examine the origin of the induced voltage in FigureĀ 1a,b. The staggered herringbone grooves enable rapid mixing in the microchannel by creating transverse flows [10,11]. Note that the x-direction indicates the longitudinal flow direction along the channel, while the y-direction indicates the transverse or lateral direction of the channel. Flow-induced voltages measured in devices with and without herringbone grooves were analyzed to examine the effects of the transverse flow component on voltage generation. The effects of flow rate and electrode-flow alignment were also investigated. The results suggested that flow-induced voltage generation with parallel and perpendicular alignments of the electrode with respect to the flow direction is due to different mechanisms, supporting our previous interpretation [8].


Flow-induced voltage generation over monolayer graphene in the presence of herringbone grooves.

Lee SH, Kang YB, Jung W, Jung Y, Kim S, Noh HM - Nanoscale Res Lett (2013)

Device preparation. (a, b) Schematic illustration of the test device without and with herringbone grooves. (c) Raman spectra of monolayered graphene. (d) Fabrication and assembly. (e) SEM images of herringbone grooves. (f) Four different types of device configurations according to the electrode-flow alignment and the presence of herringbone grooves.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4225506&req=5

Figure 1: Device preparation. (a, b) Schematic illustration of the test device without and with herringbone grooves. (c) Raman spectra of monolayered graphene. (d) Fabrication and assembly. (e) SEM images of herringbone grooves. (f) Four different types of device configurations according to the electrode-flow alignment and the presence of herringbone grooves.
Mentions: Here, we modified the flow to have a transverse component by introducing staggered herringbone grooves in the microchannel to further examine the origin of the induced voltage in FigureĀ 1a,b. The staggered herringbone grooves enable rapid mixing in the microchannel by creating transverse flows [10,11]. Note that the x-direction indicates the longitudinal flow direction along the channel, while the y-direction indicates the transverse or lateral direction of the channel. Flow-induced voltages measured in devices with and without herringbone grooves were analyzed to examine the effects of the transverse flow component on voltage generation. The effects of flow rate and electrode-flow alignment were also investigated. The results suggested that flow-induced voltage generation with parallel and perpendicular alignments of the electrode with respect to the flow direction is due to different mechanisms, supporting our previous interpretation [8].

Bottom Line: Phys.We found that the flow-induced voltage decreased significantly in the presence of herringbone grooves in both parallel and perpendicular alignments.These results support our previous interpretation.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology, Daejeon 305-701, Republic of Korea. soohyun@kaist.ac.kr.

ABSTRACT
While flow-induced voltage over a graphene layer has been reported, its origin remains unclear. In our previous study, we suggested different mechanisms for different experimental configurations: phonon dragging effect for the parallel alignment and an enhanced out-of-plane phonon mode for the perpendicular alignment (Appl. Phys. Lett. 102:063116, 2011). In order to further examine the origin of flow-induced voltage, we introduced a transverse flow component by integrating staggered herringbone grooves in the microchannel. We found that the flow-induced voltage decreased significantly in the presence of herringbone grooves in both parallel and perpendicular alignments. These results support our previous interpretation.

No MeSH data available.