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Femtosecond laser rapid fabrication of large-area rose-like micropatterns on freestanding flexible graphene films.

Shi X, Li X, Jiang L, Qu L, Zhao Y, Ran P, Wang Q, Cao Q, Ma T, Lu Y - Sci Rep (2015)

Bottom Line: This unique hierarchical layering structure of graphene films provides great possibilities for generation of tensile stress during femtosecond laser ablation to roll up the nanoflakes, which contributes to the formation of microflowers.More importantly, this technique enables fabrication of the large-area patterned surfaces at centimeter scales in a simple and efficient way.This study not only presents new insights of ultrafast laser processing of novel graphene-based materials but also shows great promise of designing new materials combined with ultrafast laser surface patterning for future applications in functional coatings, sensors, actuators and microfluidics.

View Article: PubMed Central - PubMed

Affiliation: Laser Micro/Nano Fabrication Laboratory, School of Mechanical Engineering, Beijing Institute of Technology, Beijing 100081, PR China.

ABSTRACT
We developed a simple, scalable and high-throughput method for fabrication of large-area three-dimensional rose-like microflowers with controlled size, shape and density on graphene films by femtosecond laser micromachining. The novel biomimetic microflower that composed of numerous turnup graphene nanoflakes can be fabricated by only a single femtosecond laser pulse, which is efficient enough for large-area patterning. The graphene films were composed of layer-by-layer graphene nanosheets separated by nanogaps (~10-50 nm), and graphene monolayers with an interlayer spacing of ~0.37 nm constituted each of the graphene nanosheets. This unique hierarchical layering structure of graphene films provides great possibilities for generation of tensile stress during femtosecond laser ablation to roll up the nanoflakes, which contributes to the formation of microflowers. By a simple scanning technique, patterned surfaces with controllable densities of flower patterns were obtained, which can exhibit adhesive superhydrophobicity. More importantly, this technique enables fabrication of the large-area patterned surfaces at centimeter scales in a simple and efficient way. This study not only presents new insights of ultrafast laser processing of novel graphene-based materials but also shows great promise of designing new materials combined with ultrafast laser surface patterning for future applications in functional coatings, sensors, actuators and microfluidics.

No MeSH data available.


Related in: MedlinePlus

(a) SEM image of the biomimetic graphene microflower fabricated by a single fs laser pulse at fluence of 1.1 J/cm2. (b) Digital image of a Chinese rose. (c) The overview of processing parameters for the formation of various surface morphologies on graphene films. The pink shaded area indicates the laser exposure parameters for the formation of graphene microflowers.
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f3: (a) SEM image of the biomimetic graphene microflower fabricated by a single fs laser pulse at fluence of 1.1 J/cm2. (b) Digital image of a Chinese rose. (c) The overview of processing parameters for the formation of various surface morphologies on graphene films. The pink shaded area indicates the laser exposure parameters for the formation of graphene microflowers.

Mentions: After irradiation with a single laser pulse, a graphene microflower, exhibiting both micrometer-scale and nanometer-scale structures, could be fabricated at the laser fluence (F) of 1.1 J/cm2, as shown in Fig. 3a. Numerous turnup graphene nanoflakes were distributed around the central region of the ablated area. These graphene nanoflakes constitute the micro-sized graphene flower, which is similar to a blooming rose (Fig. 3b). The graphene microflowers could be fabricated at a relatively low pulse numbers (<100) around a wide range of laser fluences, indicated by the pink shaded area in Fig. 3c. In general, the three types of surface structures can be fabricated as shown in Fig. 3c. From the bottom to the top right, the surface morphology evolves from graphene microflowers to blind holes or nanoripples and to through holes (see the detailed structure morphologies in Supplementary Fig. S1). For comparison purpose, we also conducted laser ablation experiments on HOPG films composed of homogeneous graphene monolayers with an interlayer spacing of ~0.34 nm. The thickness of the HOPG films is ~ 13 μm, similar to that of the graphene films. In contrast to the graphene film, the microflowers were not obtained. After ablation with laser fluences ranging from 0.2 J/cm2 (slightly above the ablation threshold) to 4 J/cm2 (more than 20 times larger than the threshold), the ablated structures on HOPG films changed from smooth craters to nanoripples to through holes with the increase of the pulse number (see comparisons of the ablated structures between graphene film and HOPG film in Supplementary Fig. S1). Hence, the structures obtained on graphene films (microflowers) are totally different from that obtained on HOPG films (smooth craters) when irradiated with laser pulses at a relatively low pulse number.


Femtosecond laser rapid fabrication of large-area rose-like micropatterns on freestanding flexible graphene films.

Shi X, Li X, Jiang L, Qu L, Zhao Y, Ran P, Wang Q, Cao Q, Ma T, Lu Y - Sci Rep (2015)

(a) SEM image of the biomimetic graphene microflower fabricated by a single fs laser pulse at fluence of 1.1 J/cm2. (b) Digital image of a Chinese rose. (c) The overview of processing parameters for the formation of various surface morphologies on graphene films. The pink shaded area indicates the laser exposure parameters for the formation of graphene microflowers.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4663466&req=5

f3: (a) SEM image of the biomimetic graphene microflower fabricated by a single fs laser pulse at fluence of 1.1 J/cm2. (b) Digital image of a Chinese rose. (c) The overview of processing parameters for the formation of various surface morphologies on graphene films. The pink shaded area indicates the laser exposure parameters for the formation of graphene microflowers.
Mentions: After irradiation with a single laser pulse, a graphene microflower, exhibiting both micrometer-scale and nanometer-scale structures, could be fabricated at the laser fluence (F) of 1.1 J/cm2, as shown in Fig. 3a. Numerous turnup graphene nanoflakes were distributed around the central region of the ablated area. These graphene nanoflakes constitute the micro-sized graphene flower, which is similar to a blooming rose (Fig. 3b). The graphene microflowers could be fabricated at a relatively low pulse numbers (<100) around a wide range of laser fluences, indicated by the pink shaded area in Fig. 3c. In general, the three types of surface structures can be fabricated as shown in Fig. 3c. From the bottom to the top right, the surface morphology evolves from graphene microflowers to blind holes or nanoripples and to through holes (see the detailed structure morphologies in Supplementary Fig. S1). For comparison purpose, we also conducted laser ablation experiments on HOPG films composed of homogeneous graphene monolayers with an interlayer spacing of ~0.34 nm. The thickness of the HOPG films is ~ 13 μm, similar to that of the graphene films. In contrast to the graphene film, the microflowers were not obtained. After ablation with laser fluences ranging from 0.2 J/cm2 (slightly above the ablation threshold) to 4 J/cm2 (more than 20 times larger than the threshold), the ablated structures on HOPG films changed from smooth craters to nanoripples to through holes with the increase of the pulse number (see comparisons of the ablated structures between graphene film and HOPG film in Supplementary Fig. S1). Hence, the structures obtained on graphene films (microflowers) are totally different from that obtained on HOPG films (smooth craters) when irradiated with laser pulses at a relatively low pulse number.

Bottom Line: This unique hierarchical layering structure of graphene films provides great possibilities for generation of tensile stress during femtosecond laser ablation to roll up the nanoflakes, which contributes to the formation of microflowers.More importantly, this technique enables fabrication of the large-area patterned surfaces at centimeter scales in a simple and efficient way.This study not only presents new insights of ultrafast laser processing of novel graphene-based materials but also shows great promise of designing new materials combined with ultrafast laser surface patterning for future applications in functional coatings, sensors, actuators and microfluidics.

View Article: PubMed Central - PubMed

Affiliation: Laser Micro/Nano Fabrication Laboratory, School of Mechanical Engineering, Beijing Institute of Technology, Beijing 100081, PR China.

ABSTRACT
We developed a simple, scalable and high-throughput method for fabrication of large-area three-dimensional rose-like microflowers with controlled size, shape and density on graphene films by femtosecond laser micromachining. The novel biomimetic microflower that composed of numerous turnup graphene nanoflakes can be fabricated by only a single femtosecond laser pulse, which is efficient enough for large-area patterning. The graphene films were composed of layer-by-layer graphene nanosheets separated by nanogaps (~10-50 nm), and graphene monolayers with an interlayer spacing of ~0.37 nm constituted each of the graphene nanosheets. This unique hierarchical layering structure of graphene films provides great possibilities for generation of tensile stress during femtosecond laser ablation to roll up the nanoflakes, which contributes to the formation of microflowers. By a simple scanning technique, patterned surfaces with controllable densities of flower patterns were obtained, which can exhibit adhesive superhydrophobicity. More importantly, this technique enables fabrication of the large-area patterned surfaces at centimeter scales in a simple and efficient way. This study not only presents new insights of ultrafast laser processing of novel graphene-based materials but also shows great promise of designing new materials combined with ultrafast laser surface patterning for future applications in functional coatings, sensors, actuators and microfluidics.

No MeSH data available.


Related in: MedlinePlus