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A multi-responsive water-driven actuator with instant and powerful performance for versatile applications.

Mu J, Hou C, Zhu B, Wang H, Li Y, Zhang Q - Sci Rep (2015)

Bottom Line: Meeting all these requirements in a single device remains a challenge.Its graphene oxide cells wrinkle and extend in response to water desorption and absorption, respectively.The graphene monolayer paper has potential in artificial muscles, robotic hands, and electromagnetic-free generators.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Donghua University, 201620 (People's Republic of China).

ABSTRACT
Mechanical actuators driven by water that respond to multiple stimuli, exhibit fast responses and large deformations, and generate high stress have potential in artificial muscles, motors, and generators. Meeting all these requirements in a single device remains a challenge. We report a graphene monolayer paper that undergoes reversible deformation. Its graphene oxide cells wrinkle and extend in response to water desorption and absorption, respectively. Its fast (~0.3 s), powerful (>100 MPa output stress, 7.5 × 10(5) N kg(-1) unit mass force), and controllable actuation can be triggered by moisture, heat, and light. The graphene monolayer paper has potential in artificial muscles, robotic hands, and electromagnetic-free generators.

No MeSH data available.


Related in: MedlinePlus

Characterizations of the GM film.(a–b) High-resolution XPS analysis (C 1s) of GO and rGO face of the GM film. c) XRD patterns of GO and rGO surface of the GM film. All the XRD patterns were recorded at room temperature.
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f2: Characterizations of the GM film.(a–b) High-resolution XPS analysis (C 1s) of GO and rGO face of the GM film. c) XRD patterns of GO and rGO surface of the GM film. All the XRD patterns were recorded at room temperature.

Mentions: Fig. 1b–e show surface observations of the free-standing GM paper. It has one smooth surface with a shiny metallic lustre, while the opposite surface is rough and dark. The static water contact angles (CA) of the two surfaces are about 91 and 57°, indicating hydrophobic rGO and hydrophilic GO structures, respectively. The deoxygenation of GO and rGO faces of the GM paper were proven by the detailed characterization of X-ray photoelectron spectroscopy (XPS). As shown in the XPS spectra (Fig. 2a and b), the C/O atom ratio was remarkably increased from 2.7 of GO face to 5.5 of rGO face. And the deconvoluted C 1s core-level spectra provide details about the surface functional groups present in the GO surface of the GM paper (sp2-hybridized graphitic carbons ~284.5 eV, sp3-hybridized saturatedcarbons ~285.0 eV, and carboxyl groups ~288.9 eV)2. While the C 1s core-level spectra of the face connected with Cu film shows that oxidized species decrease their concentration and the sp2 hybridization increases which is typical behavior after reducing GO. Their surface chemistry was also investigated using Raman spectroscopy (see Fig. S2c.). Raman spectra of GO and rGO faces of the GM paper. All spectra show the characteristic D- (1345 cm−1) and G-bands (1600 cm−1) of those samples. The D-band is quite intense in the rGO face, and the intensity ratios for the D and G bands (ID/IG) change from 1.12 (GO) to 1.27 (rGO). The values are both significantly larger than that of original GO sample (0.78)2. These results suggested the decrease in the average size for the sp2 domains upon the reduction of GO occurred on both sides of the GM paper and a deeper reduction in the rGO face of the GM paper in comparison to its GO face. The reduction of GO is confirmed by the Raman spectra, similar to in our previous works220. The rGO sheets assemble into a compact layered structure, because of the π-π stacking interactions of rGO. This is shown in the cross-sectional field emission scanning electron microscopy (FESEM) images in Fig. 1f and 1h. The rGO region has a high conductivity of 2347 S m−1. In contrast, oxygen-containing functionality makes the GO region nearly insulating. The GO region has a cellular structure (Fig. 1g), with sufficient room for large-scale deformation and channels for water exchange.


A multi-responsive water-driven actuator with instant and powerful performance for versatile applications.

Mu J, Hou C, Zhu B, Wang H, Li Y, Zhang Q - Sci Rep (2015)

Characterizations of the GM film.(a–b) High-resolution XPS analysis (C 1s) of GO and rGO face of the GM film. c) XRD patterns of GO and rGO surface of the GM film. All the XRD patterns were recorded at room temperature.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4379955&req=5

f2: Characterizations of the GM film.(a–b) High-resolution XPS analysis (C 1s) of GO and rGO face of the GM film. c) XRD patterns of GO and rGO surface of the GM film. All the XRD patterns were recorded at room temperature.
Mentions: Fig. 1b–e show surface observations of the free-standing GM paper. It has one smooth surface with a shiny metallic lustre, while the opposite surface is rough and dark. The static water contact angles (CA) of the two surfaces are about 91 and 57°, indicating hydrophobic rGO and hydrophilic GO structures, respectively. The deoxygenation of GO and rGO faces of the GM paper were proven by the detailed characterization of X-ray photoelectron spectroscopy (XPS). As shown in the XPS spectra (Fig. 2a and b), the C/O atom ratio was remarkably increased from 2.7 of GO face to 5.5 of rGO face. And the deconvoluted C 1s core-level spectra provide details about the surface functional groups present in the GO surface of the GM paper (sp2-hybridized graphitic carbons ~284.5 eV, sp3-hybridized saturatedcarbons ~285.0 eV, and carboxyl groups ~288.9 eV)2. While the C 1s core-level spectra of the face connected with Cu film shows that oxidized species decrease their concentration and the sp2 hybridization increases which is typical behavior after reducing GO. Their surface chemistry was also investigated using Raman spectroscopy (see Fig. S2c.). Raman spectra of GO and rGO faces of the GM paper. All spectra show the characteristic D- (1345 cm−1) and G-bands (1600 cm−1) of those samples. The D-band is quite intense in the rGO face, and the intensity ratios for the D and G bands (ID/IG) change from 1.12 (GO) to 1.27 (rGO). The values are both significantly larger than that of original GO sample (0.78)2. These results suggested the decrease in the average size for the sp2 domains upon the reduction of GO occurred on both sides of the GM paper and a deeper reduction in the rGO face of the GM paper in comparison to its GO face. The reduction of GO is confirmed by the Raman spectra, similar to in our previous works220. The rGO sheets assemble into a compact layered structure, because of the π-π stacking interactions of rGO. This is shown in the cross-sectional field emission scanning electron microscopy (FESEM) images in Fig. 1f and 1h. The rGO region has a high conductivity of 2347 S m−1. In contrast, oxygen-containing functionality makes the GO region nearly insulating. The GO region has a cellular structure (Fig. 1g), with sufficient room for large-scale deformation and channels for water exchange.

Bottom Line: Meeting all these requirements in a single device remains a challenge.Its graphene oxide cells wrinkle and extend in response to water desorption and absorption, respectively.The graphene monolayer paper has potential in artificial muscles, robotic hands, and electromagnetic-free generators.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Donghua University, 201620 (People's Republic of China).

ABSTRACT
Mechanical actuators driven by water that respond to multiple stimuli, exhibit fast responses and large deformations, and generate high stress have potential in artificial muscles, motors, and generators. Meeting all these requirements in a single device remains a challenge. We report a graphene monolayer paper that undergoes reversible deformation. Its graphene oxide cells wrinkle and extend in response to water desorption and absorption, respectively. Its fast (~0.3 s), powerful (>100 MPa output stress, 7.5 × 10(5) N kg(-1) unit mass force), and controllable actuation can be triggered by moisture, heat, and light. The graphene monolayer paper has potential in artificial muscles, robotic hands, and electromagnetic-free generators.

No MeSH data available.


Related in: MedlinePlus